Hi all,
Since the emergency patch at the beginning of the month, Steam Deck controls have been partially unusable. And it wasn't even my fault, Unity seems to have introduced some undocumented changes in their "New Input" system that messed with Steam Deck specifically (and possibly Linux in general).
So, after a partial shift back to the "Old Input" system, it works again. The march of progress, I guess.
Sorry for the delay and inconvenience!