Black Bar Over Video - Please help!

Love your help with this. 

Our developers are saying its a problem with the H5P plug in / video player. Just wondering if anyone else has experienced this problem or has any ideas of whats going wrong. 

When playing H5P videos on Chrome on a mobile device (samsung tablet and iphone) via a Wordpress site. 

eg Mobile device - Chrome - see browser details here whatsmybrowser.org/b/9EJQB6V

We've updated the H5P plugin and it hasnt fixed the problem. It doesnt happen straight away but when you skip along the video to a part further along. 

It looks like this - see image attached. You can only see the top half of the video as there is a black bar across the top.