I have a multi-montor setup with a primary landscape monitor, and a side portrait monitor. Whenever I disconnect my primary monitor (phyiscal disconnect or disabling it in the settings), the secondary monitor converts to primary (as it should), but then immediately freezes. I can move my mouse cursor, but nothing else refreshes on the display. I can still interact with the environment (ex I can pause music by clicking on a pause button, but the screen is still frozen and I cannot see that the button has been pressed). The screen will refresh if I switch to tty1 (Ctrl+Alt+F1) and back (Ctrl+Alt+F7).
This only happens when my secondary monitor is in portrait mode. Landscape mode works as intended.
I’ve tried messing with compositor settings with no success.
First thing I would try is exiting Plasma, logging in on a vtty, and removing all content from ~/.cache/, then logging back in to Plasma.
Second thing would be a repeat of first try plus deletion of ~/.local/share/kscreen.
If still no help, next thing I would try is removing from /etc/X11/xorg.con* all references to keyboard, mouse, touchpad, etc., everything having nothing directly to do with video, then restarting X.
If no help there, next I’d try uninstalling NVidia’s drivers to see if the upstream default modesetting X driver and/or the optional nouveau X driver constitute a solution. If they do, it suggests you have a question for an NVidia forum.
A workaround possibility might be disabling KScreen.
Are you using any adapters between machine outputs and displays, DVI to HDMI, or DP to HDMI maybe?
Thanks Mazda! I just got around to being able to try your fixes, and only switching int Nouveau drivers fixed the issue. Guess it must be a NVIDIA thing