SUMMARY I have an external screen that, when plugged in, I would like to exactly mirror my internal screen with a 720p resolution. But when it is unplugged, and I use only the internal screen, that should be 1080p. Somehow this does not work and it fails to switch the resolution of my internal screen -- though the exact same thing worked just fine until a week ago with a different screen. STEPS TO REPRODUCE 1. Set up internal screen to 1080p 2. Connect external screen, set both screens to 720p and move them to the same position in the screen configuration 3. Unplug external screen OBSERVED RESULT The internal screen remains at 720p EXPECTED RESULT The internal screen should switch to 1080p. If I switch it to 1080p by hand, then next time I plug in that external screen, *it* is still at 720p but the internal one remains at 1080p, which looks very wrong. SOFTWARE/OS VERSIONS Operating System: Debian GNU/Linux KDE Plasma Version: 5.25.4 KDE Frameworks Version: 5.97.0 Qt Version: 5.15.4 Kernel Version: 5.18.0-4-amd64 (64-bit) Graphics Platform: X11 Processors: 8 × Intel® Xeon® CPU E3-1505M v5 @ 2.80GHz Memory: 31,2 GiB of RAM Graphics Processor: Mesa Intel® HD Graphics P530 Manufacturer: LENOVO Product Name: 20ENCTO1WW System Version: ThinkPad P50 ADDITIONAL INFORMATION
It sounds like you want the internal screen's resolution to not be global, but rather be remembered on a per-display-arrangement basis (1080p when alone, 720p when the external monitor is connected). There's a setting for this in System Settings > Display and Monitor: "Save displays' properties: For only this specific display arrangement". If you're not using that setting, can you try it and see if that works?
I think I had that set? But anyway I am using Wayland now and couldn't reproduce the issue any more. (All I ran into is Plasma losing track of its panel, as usual... but that's another bug, probably https://bugs.kde.org/show_bug.cgi?id=356225 )
> But anyway I am using Wayland now and couldn't reproduce the issue any more. Oh that's good news!