Some games sometimes have a hard time to switch from the default desktop resolution. As a general rule, even if I setup the game as fullscreen, I set up the desktop to be the same as the desired game resolution / refresh rate (quick shortcuts using display changer does the trick). And it also allow for more stable alt tab switching.
But I never had something resembling what you describe.
lg oled55c9pla - yamaha rx-a860 - monitor audio bronze br2 (front) + brlcr (center) + br1 (surround) + b&w asw610 (subwoofer) - sharc earc audio converter - pc (ryzen 3900x / nvidia rtx 2070 super) - nvidia shield tv 2019 - apple tv 4k - sony ps4 pro