The controller lag might just be a symptom of the same problem, but it's strange regardless. Bummer. In my neck of the woods, Proton has been so good that I often find myself not even checking compatibility ratings before buying a game. I'm actually struggling to remember the last time that Proton failed me, since the things it struggles with these days, like certain kinds of anti-cheat or DRM, are the exact reasons I wouldn't buy a game even if I was on Windows. Kubuntu/AMD, if you were curious.