Youtube fullscreen splits diagonally on my MacBook Air Sierra
I watched Youtube on MacBook Air with Safari, it played 720p60 and when I go fullscreen, the video would splits diagonally. I didn't know what to do. Can you guys help me? But when I capture using Shift+command+3 this problem didn't show up.
Then I capture with my phone
Can anyone help me with this issue?
thanks
MacBook Air, 10.13.4