KDE Plasma keeps crashing after the last stable update

Goodmorning everyone.
I am writing here on the forum as, starting with the stable Manjaro update installed a few days ago, KDE Plasma started crashing quite frequently.
Whenever I perform an operation on my Desktop (rename files, open folders using the arrow at the top left of the icon, etc ...), in fact, Plasma freezes and restarts.
The same problem also occurs when I close a program, unlock the screen or change the widgets (Plasmoids) on the screen.

I tried to take a look at the logs, but in addition to the innumerable "BadWindow" of QT (which also appear on my other laptop not affected by this problem) I only noticed the plasmashell crash dump which, however, did not gave a lot of useful information to solve the problem:

01/03/20 19:25	kded5	org.kde.knotifications: warning: failed to connect to ActionInvoked dbus signal
01/03/20 19:25	yakuake	org.kde.knotifications: warning: failed to connect to ActionInvoked dbus signal
01/03/20 19:25	yakuake	org.kde.knotifications: warning: failed to connect to NotificationClosed dbus signal
01/03/20 19:25	kded5	org.kde.knotifications: warning: failed to connect to NotificationClosed dbus signal
01/03/20 19:25	plasmashell	qml: onLoaded
01/03/20 19:25	plasmashell	Could not create Plasma Calendar Plugin:  "/usr/lib/x86_64-linux-gnu/qt5/plugins/plasmacalendarplugins/holidaysevents.so"
01/03/20 19:25	plasmashell	"The shared library was not found."
01/03/20 19:25	plasmashell	Could not create Plasma Calendar Plugin:  "/usr/lib/x86_64-linux-gnu/qt5/plugins/plasmacalendarplugins/holidaysevents.so"
01/03/20 19:25	plasmashell	"The shared library was not found."
01/03/20 19:25	plasmashell	Both point size and pixel size set. Using pixel size.
01/03/20 19:25	plasmashell	Both point size and pixel size set. Using pixel size.
01/03/20 19:25	plasmashell	Both point size and pixel size set. Using pixel size.
01/03/20 19:25	plasmashell	Both point size and pixel size set. Using pixel size.
01/03/20 19:25	plasmashell	Both point size and pixel size set. Using pixel size.
01/03/20 19:25	plasmashell	trying to show an empty dialog
01/03/20 19:25	kded5	Registering "org.kde.StatusNotifierHost-3245" as system tray
01/03/20 19:25	plasmashell	Plasma Shell startup completed
01/03/20 19:25	plasmashell	Plasma Shell startup completed
01/03/20 19:25	org_kde_powerdevil	powerdevil: Screen brightness value:  255
01/03/20 19:25	org_kde_powerdevil	powerdevil: Screen brightness value max:  255
01/03/20 19:25	org_kde_powerdevil	powerdevil: Screen brightness value:  255
01/03/20 19:25	org_kde_powerdevil	powerdevil: Screen brightness value max:  255
01/03/20 19:25	plasmashell	Both point size and pixel size set. Using pixel size.
01/03/20 19:25	plasmashell	Connecting to deprecated signal QDBusConnectionInterface::serviceOwnerChanged(QString,QString,QString)
01/03/20 19:25	plasmashell	trying to show an empty dialog
01/03/20 19:25	plasmashell	file:///usr/share/plasma/shells/org.kde.plasma.desktop/contents/views/Desktop.qml:146:19: QML Loader: Binding loop detected for property "height"
01/03/20 19:25	plasmashell	file:///usr/share/plasma/shells/org.kde.plasma.desktop/contents/views/Desktop.qml:146:19: QML Loader: Binding loop detected for property "height"
01/03/20 19:25	plasmashell	trying to show an empty dialog
01/03/20 19:25	plasmashell	file:///usr/share/plasma/shells/org.kde.plasma.desktop/contents/views/Desktop.qml:146:19: QML Loader: Binding loop detected for property "height"
01/03/20 19:25	plasmashell	file:///usr/share/plasma/shells/org.kde.plasma.desktop/contents/views/Desktop.qml:146:19: QML Loader: Binding loop detected for property "height"
01/03/20 19:25	gmenudbusmenuproxy	kde.dbusmenuproxy: Ignoring window 35651643 of type 2
01/03/20 19:25	gmenudbusmenuproxy	kde.dbusmenuproxy: Ignoring window 35651658 of type 2
01/03/20 19:25	systemd-coredump	Process 3158 (plasmashell) of user 1000 dumped core.

Stack trace of thread 3158:
#0  0x00007f9e35586ce5 raise (libc.so.6)
#1  0x00007f9e36f00934 _ZN6KCrash19defaultCrashHandlerEi (libKF5Crash.so.5)
#2  0x00007f9e35586d70 __restore_rt (libc.so.6)
#3  0x00007f9e37fd5bc4 _ZNK11PlasmaQuick6Dialog9isVisibleEv (libKF5PlasmaQuick.so.5)
#4  0x00007f9e37fd5bf0 n/a (libKF5PlasmaQuick.so.5)
#5  0x00007f9e37fd81a8 n/a (libKF5PlasmaQuick.so.5)
#6  0x00007f9e35bd7540 n/a (libQt5Core.so.5)
#7  0x00007f9e35f6c183 _ZN7QWindow14visibleChangedEb (libQt5Gui.so.5)
#8  0x00007f9e35f734e9 _ZN14QWindowPrivate10setVisibleEb (libQt5Gui.so.5)
#9  0x00007f9e35f7296b _ZN14QWindowPrivate7destroyEv (libQt5Gui.so.5)
#10 0x00007f9e35f72b03 _ZN7QWindowD1Ev (libQt5Gui.so.5)
#11 0x00007f9e377c5bb7 _ZN12QQuickWindowD1Ev (libQt5Quick.so.5)
#12 0x00007f9e2c2c04ef n/a (libcorebindingsplugin.so)
#13 0x00007f9e35bcf0a0 _ZN7QObject5eventEP6QEvent (libQt5Core.so.5)
#14 0x00007f9e35f7395b _ZN7QWindow5eventEP6QEvent (libQt5Gui.so.5)
#15 0x00007f9e377d1183 _ZN12QQuickWindow5eventEP6QEvent (libQt5Quick.so.5)
#16 0x00007f9e37fd8ee4 _ZN11PlasmaQuick6Dialog5eventEP6QEvent (libKF5PlasmaQuick.so.5)
#17 0x00007f9e367cc362 _ZN19QApplicationPrivate13notify_helperEP7QObjectP6QEvent (libQt5Widgets.so.5)
#18 0x00007f9e367d5819 _ZN12QApplication6notifyEP7QObjectP6QEvent (libQt5Widgets.so.5)
#19 0x00007f9e35ba1a12 _ZN16QCoreApplication15notifyInternal2EP7QObjectP6QEvent (libQt5Core.so.5)
#20 0x00007f9e35ba4276 _ZN23QCoreApplicationPrivate16sendPostedEventsEP7QObjectiP11QThreadData (libQt5Core.so.5)
#21 0x00007f9e35bfaa84 n/a (libQt5Core.so.5)
#22 0x00007f9e33ea151e g_main_context_dispatch (libglib-2.0.so.0)
#23 0x00007f9e33ea32d1 n/a (libglib-2.0.so.0)
#24 0x00007f9e33ea3311 g_main_context_iteration (libglib-2.0.so.0)
#25 0x00007f9e35bfa0d0 _ZN20QEventDispatcherGlib13processEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE (libQt5Core.so.5)
#26 0x00007f9e35ba057c _ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE (libQt5Core.so.5)
#27 0x00007f9e35ba8586 _ZN16QCoreApplication4execEv (libQt5Core.so.5)
#28 0x000055d5abaa5dc9 n/a (plasmashell)
#29 0x00007f9e35572023 __libc_start_main (libc.so.6)
#30 0x000055d5abaa622e _start (plasmashell)

Stack trace of thread 3181:
#0  0x00007f9e34de7cf5 pthread_cond_wait@@GLIBC_2.3.2 (libpthread.so.0)
#1  0x00007f9e359cbcc4 _ZN14QWaitCondition4waitEP6QMutex14QDeadlineTimer (libQt5Core.so.5)
#2  0x00007f9e359cbda2 _ZN14QWaitCondition4waitEP6QMutexm (libQt5Core.so.5)
#3  0x00007f9e3776a56b n/a (libQt5Quick.so.5)
#4  0x00007f9e3776a7fb n/a (libQt5Quick.so.5)
#5  0x00007f9e359c5fd6 n/a (libQt5Core.so.5)
#6  0x00007f9e34de146f start_thread (libpthread.so.0)
#7  0x00007f9e3564a3d3 __clone (libc.so.6)

Stack trace of thread 3183:
#0  0x00007f9e34de7cf5 pthread_cond_wait@@GLIBC_2.3.2 (libpthread.so.0)
#1  0x00007f9e359cbcc4 _ZN14QWaitCondition4waitEP6QMutex14QDeadlineTimer (libQt5Core.so.5)
#2  0x00007f9e359cbda2 _ZN14QWaitCondition4waitEP6QMutexm (libQt5Core.so.5)
#3  0x00007f9e3776a56b n/a (libQt5Quick.so.5)
#4  0x00007f9e3776a7fb n/a (libQt5Quick.so.5)
#5  0x00007f9e359c5fd6 n/a (libQt5Core.so.5)
#6  0x00007f9e34de146f start_thread (libpthread.so.0)
#7  0x00007f9e3564a3d3 __clone (libc.so.6)

Stack trace of thread 3201:
#0  0x00007f9e34de7cf5 pthread_cond_wait@@GLIBC_2.3.2 (libpthread.so.0)
#1  0x00007f9e1f24399c n/a (radeonsi_dri.so)
#2  0x00007f9e1f243598 n/a (radeonsi_dri.so)
#3  0x00007f9e34de146f start_thread (libpthread.so.0)
#4  0x00007f9e3564a3d3 __clone (libc.so.6)

Stack trace of thread 3184:
#0  0x00007f9e3563fabf __poll (libc.so.6)
#1  0x00007f9e33ea3240 n/a (libglib-2.0.so.0)
#2  0x00007f9e33ea3311 g_main_context_iteration (libglib-2.0.so.0)
#3  0x00007f9e35bfa0d0 _ZN20QEventDispatcherGlib13processEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE (libQt5Core.so.5)
#4  0x00007f9e35ba057c _ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE (libQt5Core.so.5)
#5  0x00007f9e359c4e62 _ZN7QThread4execEv (libQt5Core.so.5)
#6  0x00007f9e376a4eab n/a (libQt5Quick.so.5)
#7  0x00007f9e359c5fd6 n/a (libQt5Core.so.5)
#8  0x00007f9e34de146f start_thread (libpthread.so.0)
#9  0x00007f9e3564a3d3 __clone (libc.so.6)

Stack trace of thread 3203:
#0  0x00007f9e34de7cf5 pthread_cond_wait@@GLIBC_2.3.2 (libpthread.so.0)
#1  0x00007f9e1f24399c n/a (radeonsi_dri.so)
#2  0x00007f9e1f243598 n/a (radeonsi_dri.so)
#3  0x00007f9e34de146f start_thread (libpthread.so.0)
#4  0x00007f9e3564a3d3 __clone (libc.so.6)

Stack trace of thread 3244:
#0  0x00007f9e34de7cf5 pthread_cond_wait@@GLIBC_2.3.2 (libpthread.so.0)
#1  0x00007f9e359cbcc4 _ZN14QWaitCondition4waitEP6QMutex14QDeadlineTimer (libQt5Core.so.5)
#2  0x00007f9e359cbda2 _ZN14QWaitCondition4waitEP6QMutexm (libQt5Core.so.5)
#3  0x00007f9e3776a56b n/a (libQt5Quick.so.5)
#4  0x00007f9e3776a7fb n/a (libQt5Quick.so.5)
#5  0x00007f9e359c5fd6 n/a (libQt5Core.so.5)
#6  0x00007f9e34de146f start_thread (libpthread.so.0)
#7  0x00007f9e3564a3d3 __clone (libc.so.6)

Stack trace of thread 3182:
#0  0x00007f9e34de7cf5 pthread_cond_wait@@GLIBC_2.3.2 (libpthread.so.0)
#1  0x00007f9e1f24399c n/a (radeonsi_dri.so)
#2  0x00007f9e1f243598 n/a (radeonsi_dri.so)
#3  0x00007f9e34de146f start_thread (libpthread.so.0)
#4  0x00007f9e3564a3d3 __clone (libc.so.6)

Stack trace of thread 3202:
#0  0x00007f9e34de7cf5 pthread_cond_wait@@GLIBC_2.3.2 (libpthread.so.0)
#1  0x00007f9e359cbcc4 _ZN14QWaitCondition4waitEP6QMutex14QDeadlineTimer (libQt5Core.so.5)
#2  0x00007f9e359cbda2 _ZN14QWaitCondition4waitEP6QMutexm (libQt5Core.so.5)
#3  0x00007f9e3776a56b n/a (libQt5Quick.so.5)
#4  0x00007f9e3776a7fb n/a (libQt5Quick.so.5)
#5  0x00007f9e359c5fd6 n/a (libQt5Core.so.5)
#6  0x00007f9e34de146f start_thread (libpthread.so.0)
#7  0x00007f9e3564a3d3 __clone (libc.so.6)

Stack trace of thread 3170:
#0  0x00007f9e34de7cf5 pthread_cond_wait@@GLIBC_2.3.2 (libpthread.so.0)
#1  0x00007f9e1f24399c n/a (radeonsi_dri.so)
#2  0x00007f9e1f243598 n/a (radeonsi_dri.so)
#3  0x00007f9e34de146f start_thread (libpthread.so.0)
#4  0x00007f9e3564a3d3 __clone (libc.so.6)

Stack trace of thread 3172:
#0  0x00007f9e34de7cf5 pthread_cond_wait@@GLIBC_2.3.2 (libpthread.so.0)
#1  0x00007f9e1f24399c n/a (radeonsi_dri.so)
#2  0x00007f9e1f243598 n/a (radeonsi_dri.so)
#3  0x00007f9e34de146f start_thread (libpthread.so.0)
#4  0x00007f9e3564a3d3 __clone (libc.so.6)

Stack trace of thread 3173:
#0  0x00007f9e34de7cf5 pthread_cond_wait@@GLIBC_2.3.2 (libpthread.so.0)
#1  0x00007f9e1f24399c n/a (radeonsi_dri.so)
#2  0x00007f9e1f243598 n/a (radeonsi_dri.so)
#3  0x00007f9e34de146f start_thread (libpthread.so.0)
#4  0x00007f9e3564a3d3 __clone (libc.so.6)

Stack trace of thread 3177:
#0  0x00007f9e34de7cf5 pthread_cond_wait@@GLIBC_2.3.2 (libpthread.so.0)
#1  0x00007f9e1f24399c n/a (radeonsi_dri.so)
#2  0x00007f9e1f243598 n/a (radeonsi_dri.so)
#3  0x00007f9e34de146f start_thread (libpthread.so.0)
#4  0x00007f9e3564a3d3 __clone (libc.so.6)

Stack trace of thread 3180:
#0  0x00007f9e34de7cf5 pthread_cond_wait@@GLIBC_2.3.2 (libpthread.so.0)
#1  0x00007f9e1f24399c n/a (radeonsi_dri.so)
#2  0x00007f9e1f243598 n/a (radeonsi_dri.so)
#3  0x00007f9e34de146f start_thread (libpthread.so.0)
#4  0x00007f9e3564a3d3 __clone (libc.so.6)

Stack trace of thread 3204:
#0  0x00007f9e34de7cf5 pthread_cond_wait@@GLIBC_2.3.2 (libpthread.so.0)
#1  0x00007f9e359cbcc4 _ZN14QWaitCondition4waitEP6QMutex14QDeadlineTimer (libQt5Core.so.5)
#2  0x00007f9e359cbda2 _ZN14QWaitCondition4waitEP6QMutexm (libQt5Core.so.5)
#3  0x00007f9e3776a56b n/a (libQt5Quick.so.5)
#4  0x00007f9e3776a7fb n/a (libQt5Quick.so.5)
#5  0x00007f9e359c5fd6 n/a (libQt5Core.so.5)
#6  0x00007f9e34de146f start_thread (libpthread.so.0)
#7  0x00007f9e3564a3d3 __clone (libc.so.6)

Stack trace of thread 3243:
#0  0x00007f9e34de7cf5 pthread_cond_wait@@GLIBC_2.3.2 (libpthread.so.0)
#1  0x00007f9e1f24399c n/a (radeonsi_dri.so)
#2  0x00007f9e1f243598 n/a (radeonsi_dri.so)
#3  0x00007f9e34de146f start_thread (libpthread.so.0)
#4  0x00007f9e3564a3d3 __clone (libc.so.6)

Stack trace of thread 3166:
#0  0x00007f9e3563fabf __poll (libc.so.6)
#1  0x00007f9e37bc1630 n/a (libxcb.so.1)
#2  0x00007f9e37bc32db xcb_wait_for_event (libxcb.so.1)
#3  0x00007f9e30eaaba1 n/a (libQt5XcbQpa.so.5)
#4  0x00007f9e359c5fd6 n/a (libQt5Core.so.5)
#5  0x00007f9e34de146f start_thread (libpthread.so.0)
#6  0x00007f9e3564a3d3 __clone (libc.so.6)

Stack trace of thread 3178:
#0  0x00007f9e34de7cf5 pthread_cond_wait@@GLIBC_2.3.2 (libpthread.so.0)
#1  0x00007f9e1f24399c n/a (radeonsi_dri.so)
#2  0x00007f9e1f243598 n/a (radeonsi_dri.so)
#3  0x00007f9e34de146f start_thread (libpthread.so.0)
#4  0x00007f9e3564a3d3 __clone (libc.so.6)

Stack trace of thread 3176:
#0  0x00007f9e34de7cf5 pthread_cond_wait@@GLIBC_2.3.2 (libpthread.so.0)
#1  0x00007f9e1f24399c n/a (radeonsi_dri.so)
#2  0x00007f9e1f243598 n/a (radeonsi_dri.so)
#3  0x00007f9e34de146f start_thread (libpthread.so.0)
#4  0x00007f9e3564a3d3 __clone (libc.so.6)

Stack trace of thread 3175:
#0  0x00007f9e34de7cf5 pthread_cond_wait@@GLIBC_2.3.2 (libpthread.so.0)
#1  0x00007f9e1f24399c n/a (radeonsi_dri.so)
#2  0x00007f9e1f243598 n/a (radeonsi_dri.so)
#3  0x00007f9e34de146f start_thread (libpthread.so.0)
#4  0x00007f9e3564a3d3 __clone (libc.so.6)

Stack trace of thread 3174:
#0  0x00007f9e34de7cf5 pthread_cond_wait@@GLIBC_2.3.2 (libpthread.so.0)
#1  0x00007f9e1f24399c n/a (radeonsi_dri.so)
#2  0x00007f9e1f243598 n/a (radeonsi_dri.so)
#3  0x00007f9e34de146f start_thread (libpthread.so.0)
#4  0x00007f9e3564a3d3 __clone (libc.so.6)

Stack trace of thread 3171:
#0  0x00007f9e34de7cf5 pthread_cond_wait@@GLIBC_2.3.2 (libpthread.so.0)
#1  0x00007f9e1f24399c n/a (radeonsi_dri.so)
#2  0x00007f9e1f243598 n/a (radeonsi_dri.so)
#3  0x00007f9e34de146f start_thread (libpthread.so.0)
#4  0x00007f9e3564a3d3 __clone (libc.so.6)

Stack trace of thread 3169:
#0  0x00007f9e34de7cf5 pthread_cond_wait@@GLIBC_2.3.2 (libpthread.so.0)
#1  0x00007f9e1f24399c n/a (radeonsi_dri.so)
#2  0x00007f9e1f243598 n/a (radeonsi_dri.so)
#3  0x00007f9e34de146f start_thread (libpthread.so.0)
#4  0x00007f9e3564a3d3 __clone (libc.so.6)

Stack trace of thread 3168:
#0  0x00007f9e3563fabf __poll (libc.so.6)
#1  0x00007f9e33ea3240 n/a (libglib-2.0.so.0)
#2  0x00007f9e33ea3311 g_main_context_iteration (libglib-2.0.so.0)
#3  0x00007f9e35bfa0d0 _ZN20QEventDispatcherGlib13processEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE (libQt5Core.so.5)
#4  0x00007f9e35ba057c _ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE (libQt5Core.so.5)
#5  0x00007f9e359c4e62 _ZN7QThread4execEv (libQt5Core.so.5)
#6  0x00007f9e37400f89 n/a (libQt5Qml.so.5)
#7  0x00007f9e359c5fd6 n/a (libQt5Core.so.5)
#8  0x00007f9e34de146f start_thread (libpthread.so.0)
#9  0x00007f9e3564a3d3 __clone (libc.so.6)

Stack trace of thread 3167:
#0  0x00007f9e3563fabf __poll (libc.so.6)
#1  0x00007f9e33ea3240 n/a (libglib-2.0.so.0)
#2  0x00007f9e33ea3311 g_main_context_iteration (libglib-2.0.so.0)
#3  0x00007f9e35bfa0d0 _ZN20QEventDispatcherGlib13processEventsE6QFlagsIN10QEventLoop17ProcessEventsFlagEE (libQt5Core.so.5)
#4  0x00007f9e35ba057c _ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE (libQt5Core.so.5)
#5  0x00007f9e359c4e62 _ZN7QThread4execEv (libQt5Core.so.5)
#6  0x00007f9e36555b28 n/a (libQt5DBus.so.5)
#7  0x00007f9e359c5fd6 n/a (libQt5Core.so.5)
#8  0x00007f9e34de146f start_thread (libpthread.so.0)
#9  0x00007f9e3564a3d3 __clone (libc.so.6)

01/03/20 19:25	systemd	systemd-coredump@6-3249-0.service: Succeeded.
01/03/20 19:25	kernel	audit: type=1131 audit(1583087103.126:104): pid=1 uid=0 auid=4294967295 ses=4294967295 msg='unit=systemd-coredump@6-3249-0 comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=success'
01/03/20 19:25	audit	SERVICE_STOP pid=1 uid=0 auid=4294967295 ses=4294967295 msg='unit=systemd-coredump@6-3249-0 comm="systemd" exe="/usr/lib/systemd/systemd" hostname=? addr=? terminal=? res=success'
01/03/20 19:25	plasmashell	kf5.kio.core: We got some errors while running testparm "Error loading services."
01/03/20 19:25	plasmashell	kf5.kio.core: We got some errors while running 'net usershare info'
01/03/20 19:25	plasmashell	kf5.kio.core: "Can't load /etc/samba/smb.conf - run testparm to debug it\n"
01/03/20 19:25	plasmashell	file:///usr/share/plasma/plasmoids/org.kde.desktopcontainment/contents/ui/FolderItemDelegate.qml:305:17: QML Label: Binding loop detected for property "width"
01/03/20 19:25	plasmashell	file:///usr/share/plasma/plasmoids/org.kde.desktopcontainment/contents/ui/FolderItemDelegate.qml:305:17: QML Label: Binding loop detected for property "width"

If it can be useful, I also write the output of the inxi -Fxxxz command:

System:    Host: Ricky-1st-Laptop Kernel: 5.5.6-1-MANJARO x86_64 bits: 64 compiler: gcc v: 9.2.1 Console: tty 1 wm: kwin_x11 
           dm: SDDM Distro: Manjaro Linux 
Machine:   Type: Laptop System: Acer product: Aspire ES1-523 v: V1.04 serial: <filter> 
           Mobo: Acer model: TRICERA_CZL v: V1.04 serial: <filter> UEFI: Insyde v: 1.04 date: 07/05/2017 
Battery:   ID-1: BAT1 charge: 25.2 Wh condition: 25.2/36.7 Wh (69%) volts: 12.8/11.4 model: COMPAL PABAS0241231 type: Li-ion 
           serial: <filter> status: Full 
CPU:       Topology: Quad Core model: AMD A8-7410 APU with AMD Radeon R5 Graphics bits: 64 type: MCP arch: Puma rev: 1 
           L1 cache: 256 KiB L2 cache: 2048 KiB 
           flags: avx lm nx pae sse sse2 sse3 sse4_1 sse4_2 sse4a ssse3 svm bogomips: 17575 
           Speed: 998 MHz min/max: 1000/2200 MHz boost: enabled Core speeds (MHz): 1: 998 2: 998 3: 998 4: 998 
Graphics:  Device-1: Advanced Micro Devices [AMD/ATI] Mullins [Radeon R4/R5 Graphics] vendor: Acer Incorporated ALI 
           driver: radeon v: kernel bus ID: 00:01.0 chip ID: 1002:9851 
           Display: server: X.Org 1.20.7 driver: radeon FAILED: ati unloaded: modesetting alternate: fbdev,vesa 
           compositor: kwin_x11 resolution: 1920x1080~60Hz, 1366x768~60Hz 
           OpenGL: renderer: AMD KABINI (DRM 2.50.0 5.5.6-1-MANJARO LLVM 9.0.1) v: 4.5 Mesa 19.3.4 direct render: Yes 
Audio:     Device-1: Advanced Micro Devices [AMD/ATI] Kabini HDMI/DP Audio vendor: Acer Incorporated ALI driver: snd_hda_intel 
           v: kernel bus ID: 00:01.1 chip ID: 1002:9840 
           Device-2: Advanced Micro Devices [AMD] FCH Azalia vendor: Acer Incorporated ALI driver: snd_hda_intel v: kernel 
           bus ID: 00:14.2 chip ID: 1022:780d 
           Sound Server: ALSA v: k5.5.6-1-MANJARO 
Network:   Device-1: Realtek RTL8111/8168/8411 PCI Express Gigabit Ethernet vendor: Acer Incorporated ALI driver: r8168 
           v: 8.048.00-NAPI port: 2000 bus ID: 01:00.0 chip ID: 10ec:8168 
           IF: enp1s0 state: down mac: <filter> 
           Device-2: Qualcomm Atheros QCA9377 802.11ac Wireless Network Adapter vendor: Lite-On driver: ath10k_pci v: kernel 
           port: 2000 bus ID: 02:00.0 chip ID: 168c:0042 
           IF: wlp2s0 state: up mac: <filter> 
Drives:    Local Storage: total: 931.51 GiB used: 74.00 GiB (7.9%) 
           ID-1: /dev/sda vendor: Toshiba model: MQ01ABD100 size: 931.51 GiB speed: 6.0 Gb/s rotation: 5400 rpm 
           serial: <filter> rev: 5J scheme: GPT 
Partition: ID-1: / size: 906.94 GiB used: 74.00 GiB (8.2%) fs: ext4 dev: /dev/sda2 
           ID-2: swap-1 size: 8.80 GiB used: 0 KiB (0.0%) fs: swap dev: /dev/sda3 
Sensors:   System Temperatures: cpu: 57.8 C mobo: N/A gpu: radeon temp: 51 C 
           Fan Speeds (RPM): N/A 
Info:      Processes: 201 Uptime: 15m Memory: 6.75 GiB used: 1.68 GiB (24.9%) Init: systemd v: 242 Compilers: gcc: 9.2.1 
           Shell: bash (sudo) v: 5.0.16 running in: yakuake inxi: 3.0.37

I thank you in advance for your help.

I would try this first, most people play with settings and break something
system settings -> global theme-> choose one -> check "use desktop layout from theme" apply
if it does not help I would delete KDE config file in /Home

Also try to create a new user and use it for a while if problem occurs it is not KDE settings.

I tried to reset the layout of the desktop through the steps you mentioned to me and the Plasma desktop crashed definitively (the background is black and the panels are no longer visible despite the windows and Latte Dock remaining perfectly functional).
I tried then to look for the KDE configuration file in the Home, but there is only the "kde4" folder. Exactly, which file are you referring to?

.               .bash_profile         crash.log     .esd_auth     Git                 .icon                 .local           .netrc              .pki               PycharmProjects           .steam        'VirtualBox VMs'   .xine
 ..              .bashrc               .designer     .eteks        .gitconfig          .icons                .logcatch       'NexxonTech Cloud'   Postman           'Python Browser Creator'   .steampath     .vnc              .xinitrc
 .android        .cache                .dir_colors   .face         .gitkraken          Immagini              Modelli          .npm                print.pdf          .python_history           .steampid      .vscode-oss
 .anydesk        .config               Documenti     .face.icon    .gnupg              .jak                  .mozilla         .omnidb             .profile           Scaricati                 .subversion    .vuerc
 .atom           .conky                .dosbox       .fltk         .gtk-bookmarks      .java                 Musica           .packettracer      'Progetti Godot'    scripts                   .swt           .wget-hsts
 .bash_history   .conkyrc              .dvdcss       .fonts        .gtkrc-2.0          JEF53K004-E11@6.jpg   .mysql           packettracer        Pubblici           Scrivania                 .thunderbird   .Xauthority
 .bash_logout    .conkyrc-1578417463   .eclipse      .fonts.conf   .harmattan-assets   .kde4                 .mysql_history   PBCProjects         .PyCharmCE2019.2   .ssh                      Video          .Xclients

Personally I would delete everything in /Home what starts with . but it is like creating new user, every setting will be lost in every application in whole DE. For me it was always the easiest way then to try to fix what is broken who knows where.
I am not guru I try to fix things as easy as it can be and it depends how long will you tweak you KDE to your liking. There are also kde configs in .config

try first to create new user

maybe do not delete .steam and other what are not certain KDE settings.

I tried to create a new user, but the problems are always the same...

So not KDE settings, some gurus will have to help.

I guess so.
Thanks anyway for the advices.

There is a little laptop that seems to have the same issue here ..

Login from SDDM seems to work (though maybe slow?) but then if desktop shows, it continually fails until I am left with black screen and cursor .. seems hotkeys still work though.
I have the same libpthread.so errors.

(trying to reset plasma settings, clearing .cache, did not help)

Here is pastebin and things:
https://pastebin.com/e0Hmfnxq

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