Hmmm, boilerplate have you verified your game files? Also before mucking with it too much back up your save files.
Personally I’m on Proton Experimental for Satisfactory, maybe try that too?
Beyond that I wonder if there’s a setting you had that has changed now, like if you were running DX12. Try starting with the -vulkan flag to force it to use vulkan on start.
Beyond that, take a snapshot of your INI files the proton area for Satisfactory, that should generate new ones allowing you to start clean… (Stored at ~/.steam/steam/steamapps/compatdata/526870/pfx/drive_c/users/steamuser/AppData/Local/FactoryGame/Saved/Config/Windows by default)
All else fails, I’d fully uninstall the app and then reinstall it - forcing a clearing of everything and restarting.
It’s working for me on my 3090, on PopOS, I know these are kinda boilerplate issues but gotta start somewhere I guess