PS4 and PS5 controllers were detected but they are basically not usable. Buttons are super sensitive and I basically get stuck in the options menu if I hit start during playing. Camera is also broken since the stick axes drift when I'm not actively moving them, so my camera always wants to point up.

Xbox One controller seems to work fine generally speaking.

Not sure if this is a Proton issue or a game issue.

I'm not sure if it was directly related, but I had some weird stability issues that seemed to be specific to when the Xbox One was plugged in. The game froze once when I swapped from the PS5 controller to the Xbox One controller (both connected via USB). There were also a handful of times that I got a black screen instead of the title screen after the company logos with the Xbox One controller connected but I didn't notice the same with either the PS4 or PS5 controller.