KDE PLasma second Desktop-wallpaper stays black & no menu

[pappl]

Hi,
i’m running Manjaro KDE with two monitors.
Since weeks the second monitor doesn’t show a wallpaper, only black screen.
I can’t right click on this second desktop and get into the rightclick menu to do anything.
But i can drag windows on this second screen and work like normal without any graphics issues.

Once every 20th reboot i get both wallpapers and it works, but most of the time not.
Unplugging the second monitor helps, and solves the issue for several reboots until it happens again.
Switched Kernels from LTS, 5.12, 5.13, 5.14, always same issue.

How can i solve this?

inxi -Fz
System:    Kernel: 5.14.0-0-MANJARO x86_64 bits: 64 Desktop: KDE Plasma 5.22.5 Distro: Manjaro Linux 
Machine:   Type: Desktop Mobo: ASRock model: A300M-STX serial: <filter> UEFI: American Megatrends v: P3.60K date: 07/22/2020 
CPU:       Info: Quad Core model: AMD Ryzen 5 3400G with Radeon Vega Graphics bits: 64 type: MT MCP cache: L2: 2 MiB 
           Speed: 1261 MHz min/max: 1400/3400 MHz Core speeds (MHz): 1: 1261 2: 1261 3: 1261 4: 1258 5: 1261 6: 1261 7: 1329 
           8: 1261 
Graphics:  Device-1: Advanced Micro Devices [AMD/ATI] Picasso driver: amdgpu v: kernel 
           Display: x11 server: X.Org 1.20.13 driver: loaded: amdgpu,ati unloaded: modesetting resolution: 1: 1920x1080~60Hz 
           2: 1920x1080~60Hz 
           OpenGL: renderer: AMD Radeon Vega 11 Graphics (RAVEN DRM 3.42.0 5.14.0-0-MANJARO LLVM 12.0.1) v: 4.6 Mesa 21.2.1 
Audio:     Device-1: Advanced Micro Devices [AMD/ATI] Raven/Raven2/Fenghuang HDMI/DP Audio driver: snd_hda_intel 
           Device-2: Advanced Micro Devices [AMD] Family 17h HD Audio driver: snd_hda_intel 
           Sound Server-1: ALSA v: k5.14.0-0-MANJARO running: yes 
           Sound Server-2: PulseAudio v: 15.0 running: yes 
Network:   Device-1: Intel Wireless-AC 9260 driver: iwlwifi 
           IF: wlp3s0 state: up mac: <filter> 
           Device-2: Realtek RTL8111/8168/8411 PCI Express Gigabit Ethernet driver: r8169 
           IF: enp4s0 state: down mac: <filter> 
Bluetooth: Device-1: Intel Wireless-AC 9260 Bluetooth Adapter type: USB driver: btusb 
           Report: rfkill ID: hci0 state: up address: see --recommends 
Drives:    Local Storage: total: 953.87 GiB used: 343.24 GiB (36.0%) 
           ID-1: /dev/nvme0n1 vendor: Silicon Power model: SPCC M.2 PCIe SSD size: 953.87 GiB 
Partition: ID-1: / size: 468.3 GiB used: 343.24 GiB (73.3%) fs: ext4 dev: /dev/nvme0n1p2 
           ID-2: /boot/efi size: 299.4 MiB used: 280 KiB (0.1%) fs: vfat dev: /dev/nvme0n1p1 
Swap:      Alert: No swap data was found. 
Sensors:   System Temperatures: cpu: 48.0 C mobo: N/A gpu: amdgpu temp: 36.0 C 
           Fan Speeds (RPM): fan-1: 0 fan-2: 0 fan-3: 0 fan-4: 0 fan-5: 0 
Info:      Processes: 235 Uptime: 11m Memory: 23.41 GiB used: 1.86 GiB (8.0%) Shell: Bash inxi: 3.3.06 

[AndreasH59]

same here with triples, nvidia prop driver 470.63.01, Kernel 5.13
After logoff and on again screens are back to normal, so i think there maybe some race condition ?

looks like an old bug reintroduced again

https://kde-bugs-dist.kde.narkive.com/0TmpKQBH/plasmashell-bug-353975-new-black-screen-on-second-display

my workaround until fix , restart plasma
kquitapp5 plasmashell && kstart5 plasmashell

[pappl]

@AndreasH59

my workaround until fix , restart plasma
kquitapp5 plasmashell && kstart5 plasmashell

This is the solution.
After running this command both monitors are okay again.
Thanks a lot.

Hope it will be fixed soon.

pappl

[AndreasH59]

That is no solution, just a workaround - had my middle monitor off this morning, thats new. I would really like a way to stop this happening

Made a report
https://bugs.kde.org/show_bug.cgi?id=442826