2 days ago my PC was running all games like RE 2 remake, Dragon quest XI on maximum settings 1080p 60 fps no problem, then i tried putting the windows resolution at quad HD, since my gpu can handle it, and everything got stuck on 30 fps including League of Legends (A game that can run 60 fps WITHOUT a GPU), i was playing all the games on borderless window, but then when i put league of legends on full screen, the game was back at 60 FPS. I tried it with Heroes of the storm and it was the same thing, i don't know what to do anymore, there are games that i can't play on full screen because of bugs (FF XI ZODIAC AGE) and it's really inconvenient.
I already changed back the resolution on windows to full HD, and even 720p, restarted the computer and none of them fixed the lag. Help please.
My GPU is a RX 580 8gb