I am watching a lot of Youtube videos and sometimes it happens that the video playback is a little faulty. In particular, there are large artifacts popping up within the video and these artifacts seems to show parts of the user interface (i.e. the Youtube page itself). Putting the video to fullscreen and back fixes the issue. This only happens on the Mac version, I never had this on Windows. I'm running the newest versions of High Sierra and Opera.
Did anyone else experience this?