Now that I've solved one bug with using the Wayland Plasma session, there's one more big issue I need to deal with: It appears the session will crash if I use "System Settings - Hardware - Power Management - Energy Saving - Screen Energy Saving" right after the screen powers off. The monitor will first go into standby once the mouse hasn't been moved for the given amount of minutes, but will immediately wake up afterward. When it does I can briefly see the console, followed by the login screen from which I need to log in again. This is quite problematic as I can't power off my screen to preserve its lifetime as well as electricity consumption. I looked but haven't seen any open bug reports on this... figured I'd ask here first before opening one to avoid duplication if the issue is known.

I have a 1080p / 144 Hz monitor connected via DisplayPort cable (no converters). I also have a cheap 1080p / 60 Hz VR headset connected over a DVI port (DVI to HDMI converter), it's completely disabled from the system settings and should have no influence.

Linux openSUSE Tumbleweed x64. Plasma 5.18.4. Mesa 20.0.4. Wayland 1.18 / 1.20. KWayland 5.68. AMD Radeon (TM) R9 390 Series (HAWAII, DRM 3.36.0, 5.6.2-1-default, LLVM 10.0.0).

https://bugs.kde.org/show_bug.cgi?id=420160 My report to the KDE bug tracker after confirming this is indeed an unaddressed bug with Plasma Wayland.

https://bugzilla.redhat.com/show_bug.cgi?id=1705121 Redhat bug indicating this is an issue with Wayland crashing when there are no display devices, I could confirm this is the root cause here too.