Safari fullscreen problems / videos glitching

Hi,

this isn't new, but I've had problems with Safari in Fullscreen, particularly with videos in fullscreen mode.

Before the last update, my screen would start glitching out extremely and it was almost impossible to watch videos in fullscreen. With the last update this has been improved somewhat. Now when the video goes into fullscreen it "only" glitches out once. This wouldn't be much of a problem, but every time some UI elements come in front of the video, ie volume bar or any options for netflix or youtube videos it happens again. Worst of all is that it also happens every time subtitles appear, so I can't watch videos with subtitles on without the screen glitching all the time.

What happens when the screen glitches is quite random. Sometimes it just jumps, sometimes it shows random screens, often other tabs, even ones that I closed recently, for a fraction of a second.

I don't understand why this is an issue. I've read about it on other forums but found no answer.

It only happens in Safari, so now I use Firefox instead for watching stuff. It is annoying because I like using safari. I don't get why Apple can't fix this with THEIR OWN browser.