[Portal 2] Failure to recognise controller input on Steam Deck

[RandomCatDude]

On first startup, the game worked fine, but when I opened the controller settings to change the configuration, the game froze. (but still opened the Steam Input menu) After forcing a shutdown and running the game again, it seems to completely ignore Steam Input and does not respond to any controller inputs (keyboard inputs work fine)

This happened when I was on the beta channel, but switching to Stable did not fix it. Neither did reinstalling the game, verifying game files, or making changes to the input configuration.

I'm guessing there is a cvar which has been incorrectly set and is therefore breaking Steam Input, I don't know what it would be, though, as I cannot type into the in-game console for some reason (On-screen keyboard inputs do nothing)