Proton-5.21-GE-1 GloriousEggroll

mf-install is necessary otherwise it will stuck on initial loading screen. Custom proton may not be necessary, but I didn't tested.

Following problem I stated is a problem of game itself that exists on Windows and even consoles. I highly recommend to backup your saves on every exit since I have heard that some bugs in game may corrupt save file, though I also heard that most of them were fixed but take a backup just in case.