Black screen when I get in game

So uhh recently I got a new monitor, now I have 2. One is curved and one is flat. When I tried to get in-game with both monitors connected in fullscreen mode, the loading screen works but when the game actually starts it just turns black. The resolution is at 1920x1080. I tried many things like changing compatibility settings but it still doesn't work. However, the resolution works when it's in windowed mode, just not in borderless or fullscreen. Someone help please T-T (oh yeah, it also doesn't work when I unplug the flat monitor).