Safari video player exit fullscreen flicker

Hi all,

I have noticed a minor (although bothersome) issue relating video playback in Safari. Exiting fullscreen mode of a video player makes Safari flicker each time.

If have tested this with Youtube and video players on other websites (all in Safari, it does not seems to effect other browsers in the same way). Playing back (for instance) a Youtube video, going from fullscreen mode of the video player and back results in Safari blinking/flickering once.

This only occurs when Safari itself is in windowed mode. In fullscreen mode Safari does not blink/flicker on exit of the video player's fullscreen mode. Furthermore it is just the Safari application that flickers, not the whole screen.

I have replicated this on several MacBook Pro's. All running the latest version of macOS (High Sierra) and Safari (11.0.3).

A video I recorded of the issue:

https://streamable.com/qijks

I was wondering if this is a known problem and if anyone knows a solution.

It is of course not a major issue, but after watching several videos it becomes noticeable and rather annoying.

(I was thinking the problem might have something to do with HTML5, flash or hardware acceleration.)