Quick fix attempt : from game mode, before starting the game, go to the game launch options, there’s one option to configure launching at various resolutions. Try to tell it to override with a specific one or even the “native” one, and it should fix things.

I had an issue similar when hooking my deck up to my 4K tv and playing Castle Crashers with family. It was only going up to 1280x800 until I made that change. Then it supported resolution up to 4K without issue.