Can't set lower resolution

I have a 4k monitor that I use for work, but for gaming, I always put my games in fullscreen 1440p because I don't have a 3090 to run 4k properly. Unfortunately, this game forces me into the 4k resolution unless I choose windowed, which is a horrible way to play.... so not an option.

I've tried manually changing the game settings file, but it still resets to 4k.