https://bugs.winehq.org/show_bug.cgi?id=46361
--- Comment #36 from Zebediah Figura z.figura12@gmail.com --- Yes, Proton uses Wine 4.2. The last released version is Wine 4.5. That's one month and a half old. Whether or not that's "old" according to some arbitrary cutoff point, there are still some changes to the joystick stack that have happened in that month and a half.
Again, it's not difficult to see what's different between Proton and Wine. I can do that just by looking at git logs. What I cannot easily do is determine which of those changes is responsible for causing this bug, or fixing it. This is why I need to ask for help of a different nature.