Question Playing games in fullscreen or borderless window causes videos in browsers to lag ?

[KRSx360]

Every time I play a game in fullscreen or borderless window the video I'm watching starts to lag but if I launch games in windowed mode it fixes the issue.

 

[Koekieezz]

Every time I play a game in fullscreen or borderless window the video I'm watching starts to lag but if I launch games in windowed mode it fixes the issue.

what browser did you use?