FSR2 scaling mode resetting after full screen apply

[netherportal40]

After I alt-tab away from the game, when I alt tab back I "lose" the fullscreen so I gotta hit "apply settings" button in display, this is fine as I guess full screening again may be problem with my OS. Thing is that every time I "apply settings" not changing resolution or anything, the Scaling mode of FSR2 changes itself back to 1x, so I get half the fps.

I play on linux, using proton experimental.