If you are able to reproduce this behavior, please make sure and report it via the Feedback app on the console, as that data is essential for the developers to investigate further. Also, is that the only video app where this behavior occurs?
I have reported before. And it happens on YouTube too.
If you are still seeing the same behavior with the most recent update released yesterday, make sure you report it via the Feedback app and be specific as to what notifications you are seeing while watching videos.