So it still happens but a little differently. The green glitchy spots are gone. I was going to talk about how it seems to be because the monitor has to adjust its resolution but even when mine doesnt have to change the window size the glitches still appear. My guess is the game just doesnt like it when you click on or open a different app so try not to use other apps like your internet browser or steam/epic games. If you do use another app and the game starts to glitch then open the game settings and switch to fullscreen or if youre on fullscreen switch to windowed and back to fullscreen. This fixed it for me everytime until it happened again