Shared screen - Audio only, no video recording

Hi, I'm currently undertaking some training of which I've set up Skype meetings with the Trainer and trying to record. I open the skype meeting then once the trainer has shared screen hit the record button - to get a full video recording of the training.

Issue:

Once the recording has finished some recordings are only showing audio only (which isn't much use) and no video - It says "At this point in the meeting, no one was presenting or sharing video" even though I'd clearly been through the training and seen everything on the Trainers screen.

Sometimes it works and I get video as well as audio and other times audio only (again which is no use)

Can someone advise if I'm missing something simple or if this is a known glitch with skype.

Cheers,

J