Video recording only recorded voice of participants on Mobile

sungar  Hello!  In reviewing other posts where users have had the same issues, I came across these two suggestions:

1) Start the recording before sharing your screen. Once you’ve stopped the recording, please don’t hang up the meeting yourself (if you’re the one who has started the recording) until it has saved otherwise it stops saving [I think this is why we end up with audio only and not video].

Saving does take some time particularly if it’s a longer recording. Be patient!! You can see whether it has saved by looking in the meeting chat. All the participants can leave the meeting; the ‘recorder’ just needs to make sure they stay in until the meeting has recorded. Only when it says recording has saved can you exit the meeting. [So there should be two messages in the chat. One to say that the recording has stopped and a second to say that the recording is ready.]

2) 3 April there was a message in the admin health center where it said that there was a problem with recordings. The message was closed on 3 April and it should be fixed. I can't find any more message that there was a "known" problem with recorded meetings.
If you still have these problems I would suggest to create a support call. The best way to contact support is through the Microsoft 365 admin portal, https://admin.microsoft.com and click the ? at the top right corner next to your name.  I did it a few times and within 30 minutes or so you will be contacted by a support engineer to ask for the details. 

I hope one of these suggestions solves your issue.  Thank you for being part of the community!