i know but i got this issue in alot of games and its not about reducing graphics settings since an rx 480 should be able to do enter the gungeon with 0 problems and i know that borderless aint real fullscreen but alot of games doesnt have real fullscreen so when using alt + enter it just switches between windowed and borderless in some games here is someone with a simular issue but he got nvidia https://forums.tomshardware.com/threads/certain-games-feel-like-theyre-stuttering-low-fps-even-with-high-fps-in-windowed-borderless-mode.3300778/?view=date but i dont know if he solved it or how he solved it