Help with the YouTube app on the Umi London

A

AC Question

I have recently purchased the Umi London and the only problem i seem to have with it at the moment is video playback on the YouTube app. Anytime i try to view a video which is above 480p e.g 720p60fps the video will play for around 10seconds before it freezes and only the sound continues to play. I was wondering if this is an issue with the phone not being able to play 60fps or the YouTube app has a bug at this moment in time.

Sidenote: i tried youtube on the chrome browser and it would only play 480p as well