For the first few launches everything was fine, but after that point the game began launching in a reduced portion of the screen (only in gaming mode). Bumping up resolution through library settings didn't help, weirdly though disabling and reenabling v-sync fixes the issue, along with ensuring borderless is enabled. This eventually stops working too but deleting proton files through library settings seems to fix this too. I recommend leaving resolution on at least 1080p due to some quality issues in the first game of the trilogy.