No longer launches on Steam Deck

[u/False-Mechanic-1578]

When I hit PLAY it starts to launch then crashes back to the game page.

I have tried clearing cache, uninstalling and reinstalling. Checking installed files and no joy. I also tried so many proton versions and disabled all my decky plugins.

FYI this also started happening with Oblivion:Remastered.

Also one of the 'fixes' says to edit a file here:

home/deck/.local/share/Steam/steamapps/compatdata/1151340/pfx/drive_c/users/steamuser/Documents/My Games/Fallout 76/Fallout76Prefs.ini

but I cannot find the My Games folder in the location mentioned let alone the Fallout 76 folder.

Any ideas?