Teams not showing video of other person or screen sharing

I have one user who cannot see anyone's video feed. Others can view his video but he cannot see anyone's video. I also tried to screen sharing with him and I is not able to see screen sharing also. All he sees is black screen with Person Name under a circle. 

He has been working without an issue for a long time on same laptop and office but this problem started last week.

I asked him to use office.com and use web teams, the result was that he could see other users, so the internet settings for his account was ok.

I then proceeded to uninstall office and then reinstall office on his laptop. This fixed the issue and now he can see other users video.