Hey, I'm trying to play GTA SA on Steam Linux with Proton, but when I run the game, it appears as if it is already open, without showing anything on the screen.
I recently had this exact same issue. In the end, I am not sure what fixed it.
I completely removed and reinstalled Steam (APT, not FLatpak) and I removed and reinstalled the games I was having trouble with.
I completely removed all my configurations in between.
After performing all of that - Everything is now back to working. I never did narrow down what the exact issue was.
You can start backing up your games (if they are on an extern place you only need to backup save files if you're not using the cloud function in Steam), then uninstalling Steam and then remove .steam from your home folder.
Afterwards