I switch back to 2x 25 inch 144Hz monitors and use Manjaro KDE. First of all I thought my AMD 6600XT was the problem or maybe Kernel 5.13 but I try Cinnamon and there was no issue at all.
So, whats the problem?
after reboot/start, sometimes my second screen is black or got a wallpaper, which I never chose, one time it was the stock one, its working but changing the wallpaper almost every time I boot/restart
when the screens turn off (go in standby) anything is broken after they turn on again. I get huge borders on any window, this sometimes, not every time
when I open Spotify or a Browser, it’s unreal small, like 400x200 (need always to maximize)
going in standby means all effects are gone after I turn monitor on again
I update KDE and now I use 5.14 but nothing helps.
When the effects are gone I need to press shift + alt + F12 and anything works again.
I thought maybe it’s a AMD RX6000 problem and will be fix in future, because I only find issues like that with the new cards. Maybe someone can help me or confirm it.
There is an old bug in KDE, try to enable Background Contrast desktop effect (make sure it is ticked) in System Settings → Workspace Behavior → Desktop Effects. Once it is ticked, make sure the compositor in enabled in Display and Monitor → Compositor. Reboot and see if it still ‘breaks’ the desktop effects when monitor is plugged/unplugged/shutdown.
You can set windows rules for specific program, right click the window title bar, go to Additional Actions, and here you can select Window Rules, and add rules (like the windows size).
//EDIT: on my side Spotify remembers its window position and size so I don’t know why it doesn’t on yours. Pretty much the same with most/all programs.
so kde has problems with multi-monitor setups, not that surprising.
If you’re using wayland, try using X, if you’re using X, try using wayland.
if neither of these help you can try kwinft (it’s not entirely stable though so it could crash on you sometimes) it might handle multiple displays better.
If it comes down to it though, just use something else than kde.
I have pretty much the same issues when it comes to Monitors going to Sleep resulting in Refreshrate being wrong and Effects not working anymore.
My only solution was to disable Monitor Standby in the Energy-Settings - I personally don’t mind it not going to “Sleep”.
Then, when it comes to Applications like Dolphin starting not on the primary Screen and starting in a wrong resolution resulting in it being cut off because of different monitor sizes: I had to go into the Settings → Window Management → Window Rules and set a custom Window Rule for all buggy applications.
It’s not great. Multi Monitor setups don’t get much love sadly. In the past years it was also very recent, that Highrefreshrate Monitors got a bit of love by Linux Devs - but it’s still not perfect.
