the game actually runs in that resolution. See, that your window at the top right corner doesnt have the "round" edge as on the left side. Also the title is not centered. When you move the window, you see that the game runs at the set resolution...
Could you check and see if it also doesnt woek in full screen mode?
I guess there is an issue with the DPI / resolution settings conflicting with the game.
Also consider if a 4k game is really the way to go. Thats really resource heavy for 2D sprites which needs to load at scene load.