This is for both KDE and Gnome. I have been running Manjaro Gnome as a dual boot with a fair amount of stability until the last update where everything has gone to hell. The basic issue being unable to boot into the OS. I have reinstalled the OS now a half dozen times. 3 times KDE, 3 times Gnome. After just the update and a reboot, the system hangs at the GUI screen just before the desktop loads. I’m able to get into the desktop usually the first time, but after that, no dice. This is happening on Gnome and KDE. So both are now unusable to me and I’m back in MacOS Catalina on my 2013 MB Pro Retina, 15’, 16GB, 1TB SSD. My graphics are NVIDIA GeForce GT 650M 1 GB & Intel HD Graphics 4000 1536 MB. I’m installing the Open Source drivers instead of Nvidia as i’ve never been able to get to the desktop when running Manjaro on the USB stick for install when trying the Nvidia drivers.
Update: I can install and run Xfce just fine. I can reboot and not have any issues getting back into my desktop.