The resolution issue is fixed, but there is still a scaling bug.
My monitor is 21:9 3840x1600
Game runs fine in borderless mode at 2844x1600 (16:9 with black bars on the side)
But in fullscreen mode the black bars are too big and the game displays in 1:1 or something like that and looks distorted.
The real issue is, that i had to add 2844x1600 as a custom resolution in the nvidia control panel. In other games it’s possible to select my native resolution (3840x1600) and the game callculates the nearest resolution for the supported aspect ratio(16:9), in this case 2844x1600 and displays correctly with black bars on the side.
I hope this gets fixed at some point. I guess everyone with an 21:9 or 21:10 monitor will face this problem.