Created attachment 145765 [details] Screenshot SUMMARY As you can see in the screenshot, on the left monitor there's the Firefox window and the panel and on the right TV (HDMI) there's the Systemsettings. Originally, the Firefox window was on the right (TV) and the Systemsettings on the left (DP monitor): STEPS TO REPRODUCE 1. Plasma Wayland, 200% scaling, DisplayPort monitor 2. Attach a TV to the HDMI port and expand the screen to the right 3. Open the Systemsettings and the Firefox on the DisplayPort monitor, move the latter to the TV (maximized) 4. Disconnect the DisplayPort cable OBSERVED RESULT The panel moved to the TV, everything looked fine. STEPS TO REPRODUCE 5. Connect the DisplayPort again OBSERVED RESULT The panel moved back to the DisplayPort monitor, as expected. However, the Firefox window moved from the TV to the Display monitor as well and Systemsettings window moved in the other direction from the DisplayPort monitor to the TV. Also the background wallpaper on the TV vanished and there are graphical artifacts (black bars) on the Systemsettings window. EXPECTED RESULT Systemsettings on the DisplayPort monitor, Firefox on the TV, no-gone wallpaper and no graphical glitches. SOFTWARE/OS VERSIONS Linux/KDE Plasma: KDE Neon Testing KDE Plasma Version: 5.23.90 KDE Frameworks Version: 5.91.0 Qt Version: 5.15.3 ADDITIONAL INFORMATION Wayland DisplayPort Monitor: 3840x2160@200% TV: 1920x1080@100%
Created attachment 145766 [details] Screenshot: After minimizing and restoring the Systemsettings window After minimizing and restoring the Systemsettings window, at least the graphical glitches on this particular window were gone.
Created attachment 145768 [details] Screenshot: Afte turning off and back on the TV After turning off and back on the TV, all windows were on the DisplayPort monitor and the background wallpaper of the TV reappeared. However, the Systemsettings window was rendered at a lower resolution. All this is easily reproducible for me. If you need specific logs, please let me know, so I can provide you with everything you need to fix these last papercuts. :)
> Also the background wallpaper on the TV vanished That's a separate issue, likely Bug 371717.
Created attachment 145880 [details] KWin support information (DP + HDMI attached)
Today, with the latest updates, I can no longer reproduce the graphical artifacts, nor the gone containment. Just, when unplugging all the HDMI, all windows go to the DP and stay there even after plugging the HDMI back in. However, when the Systemsettings was on the low res HDMI monitor before, it's rendered in lower resolution after plugging out the HDMI monitor. I will open a new bug report for that.