Steam should be loading a separate controller config for every game, or at very least loading a default profile of “every button is literally the same as an Xbox controller”. A weird SteamInput config shouldn’t affect across all games, I think.

Does it act up in Desktop mode? How about if Steam is closed, and you play something from Heroic?

It’s possible that a hardware fault is sending insane inputs. Bad connections to the controller-sub-boards? The controller microchip just going batty?