I have been having issues with the Compositor on Garuda. I have the "enable at startup" checked, but every time I turn the computer on or return from screen saver I have to retoggle it to get the compositor working. Is there something I'm missing?
The main reason I use it is for an addon for a game requires the compositor to be active otherwise the screen is black and unusable.
did you always have this issue? render backend set to OpenGL 3.1 in compositor settings?
If it's happening without running a game, I'd guess it's a driver-related issue crashing KWin and reverting that setting. Maybe dmesg or journalctl logs will tell you something. I would make sure only needed drivers are installed and remove/blacklist what's unneeded if it's potentially conflicting. And try another kernel if you haven't already.