Created attachment 170424 [details] Screenshot of monitor setup SUMMARY When attaching an external HDMI monitor (in fact via USB-C) the monitor is often mis-recognized, so that its actual resolution is not read and the resolution is set to 1024x768 even if the monitor is a 4k one. Even worse than that, when this happens, the internal and the external screen get auto-layed-out with a huge gap in between, so that it is not even possible to pass the mouse cursor from one to the other. STEPS TO REPRODUCE 1. Attach external monitor 2. Configure it for the appropriate 4k resolution 3. Detach external monitor 4. Reattach it OBSERVED RESULT Occasionally the external monitor resolution gets set up in a wrong way (1024x768) and a gap is created between the screens. EXPECTED RESULT The external monitor resoution should be set up correctly and, most important, in the layout there should be no gaps. Operating System: Manjaro Linux KDE Plasma Version: 6.0.5 KDE Frameworks Version: 6.2.0 Qt Version: 6.7.1 Kernel Version: 6.9.3-3-MANJARO (64-bit) Graphics Platform: Wayland Processors: 16 × AMD Ryzen 9 6900HS with Radeon Graphics Memory: 30.6 GiB of RAM Graphics Processor: AMD Radeon Graphics Manufacturer: ASUSTeK COMPUTER INC. Product Name: ROG Zephyrus G14 GA402RK_GA402RK System Version: 1.0
The huge gap is caused by the monitor changing resolution unexpectedly, and that not being handled properly; this is Bug 479952. The resolution changing is a separate bug which we do expect to be fixed in Plasma 6.1. *** This bug has been marked as a duplicate of bug 479952 ***
What is a bit weird is that in my case the scale factor of the laptop internal monitor was not touched at all. It is at 150% and it has always been so. Hence the ultimate reason for my problem is most likely not bug 479952 even if the cure might end up being similar. Another reason for saying that the issue might be different is that I do not see it happening every time but only occasionally (I would say between 10 and 20% of the times when I attach the external monitor). I have a suspect. I think this may happen because of the time when I attach the external monitor. If I attach it while my laptop is getting out of sleep, then, occasionally, the issue. If this is the case, then there might be some sort of race.
Changing the scale and resolution of one of the monitors will both have the same effect of introducing a gap in monitors; it's got the same underlying root cause.
> Changing the scale and resolution of one of the monitors will both have the same effect of introducing a gap in monitors; it's got the same underlying root cause. Understandable, so I guess the gap issue will be fixed also for me with plasma 6.1 thanks! What remains weird is why the 4k external monitor is "transiently" seen as a 1024x768 one at connection. If I later go to the display settings, I see that its resolutions are actually read out correctly.