In chrome when I make a video full screen from a maximized window the entire screen will flicker. If I restore chrome to windowed mode and then make the video full screen there is no flickering. Same happens with gnome-mpv as well.
I have exactly the same issue with Chrome and found 2 workarounds after some research which both work for me. Unfortunately each has it’s own drawback:
option 1: Disable “hardware acceleration” in the advanced settings of Chrome
option 2: Select “use system title bar and borders” in settings of Chrome