Youtube Fullscreen with White border on Safari
I have a MacBook Pro 13-inch 2018 with Touch Bar. I have a problem when watching youtube with white border on fullscreen mode. Look like the photo below. This appeared to happen after I stop using fullscreen and reused in fullscreen again. This problem only happen in Safari but it didn't appear in Chrome. What should I do to solve this problem ?
MacBook Pro 13”, 10.14