YouTube education videos stop working after a few days

We have a YouTube education account and have various playlists all working brilliantly until this last few weeks, when now videos that are 'whitelisted' are bringing up the Education filter block page. If I create a new playlist and add the video again it works immediately, I thought it might be an anomaly but as it has happened over 10 times in quick succession across multiple playlists I'm wondering if others have had the same problem?

Which of course is becoming quite a pain for the school as staff had just starting relying on it...

Anyone else having this bother?

Cheers

Have you set this up with LGfL 2.0 (Virgin)?