I tried to jump over to KDE from gnome yesterday and have experienced a lot of issues in CS2. Maybe I am missing some shared libs or anything, if you know of fixes to the following issues I would love to hear them :)
Every so often my screen goes black while playing cs2. It remains black for a few seconds before coming back alive.
My KDE panels are appearing Infront of CS2 every time I alt tab and the only way to fix it is to go into settings and go > Windowed > back to Fullscreen.
I am running endeavourOS
Nvidia 545.29.06 on a GTX 1070ti
Sounds like a compositor issue. Look up your issues more generally with KDE instead of focusing on CS2 directly. There are some tweaks you can make with the full screen compositor that can make your experience better. Also try full screen vs windowed settings modes and see if you get any difference.
I haven’t noticed any issues with a 1080 using i3, so this definitely seems like a KDE issue. Are you getting desktop notifications when it goes black?
For the panels issue, you can launch CS2, press Alt+F3 to open the window settings, go to configure special app settings, then set an option for the app so that it always launches in fullscreen mode.
I also added a shortcut to make games fullscreen by pressing Ctrl+Enter.
I believe this is a bug with KDE and should be reported to them. The same issue is reported on Valve's repository but nothing has been done from Valve's side to fix this issue.