I checked and as far as I can tell, none of those are turned on, (mind you I am not familiar with the Nvidia and monitor settings, yet), but my other games I play find that resolution easily.
No idea why co-open does not.
The lowest resolution in the game is 320 x 200, the highest is 1280 x 1440, but there's back bars on the left and right with the highest selected, though it is the crispier looking display, compared to the ones lower.
I'm very confused, the game can't even find the 1920 x 1080 resolution.