Miracast wireless display bug while playing full screen Youtube videos in Firefox.

When in Miracast wireless display mode and while playing YouTube videos in full screen mode, some of the videos are choppy or jerky. I tried two different adapters from two different companies and the problem still exist. I tried a MS Edge browser and the problem disappears. The problem has some thing to do with the drop down toolbar on top of the screen. When the tool bar is pinned, the problem does not occur. When the tool bar is unpinned, the problem returns. Again this only happens when playing YouTube videos in full screen mode and when the tool bar is unpinned. Any help with this issue is appreciated.