I didn’t know you could set that as default but recently ai’ve been trying to make Proton work but with no efforts, until I started trying everything under the oldest version available which is 3.7 and it seems to work with almost every game, which is odd since I though maybe newer version are improving over the old ones. I guess that is the stable version or something but since they don’t let you know a lot about that kind of stuff is a guessing game more than anything.