I changed my windows resolution settings to be 2560x1440 but the game somehow ignores it and uses the full monitor size (which is 3440x1440)... Everything looks fine in windowed mode.

I changed my resolution settings through windows-os to 2560x1440 and managed to get the game started. Then I changed it back to 3440x1440 and now I get a really broken view of the game when I play it in full-screen mode. If I change the screen mode to window, the game is shown correctly. I think when the game ran without that crashes it scaled down my resolution but somehow that does not work anymore. If I change the settings to 2560x1440 the game works just fine. Is it possible that the game does not support WQHD? Would you suggest to downgrade the gpu driver?