Windows 10, after stopping screen sharing, video doesn't restart

I had a report today that after a user installed the latest Win10 updates, different clients (Chrome, Edge Chromium, Jitsi Electron) don’t restart his video stream after he stops screen sharing. Camera is transmitted fine at first, but as soon as he does screen sharing and stops that, the video doesn’t come back.

The other participants only see his view as black, he mentioned “weird patterns”. Audio still works.

Since it happens with multiple clients I am wondering if it is a Windows Defender / - Firewall issue instead.

Does anyone experience anything similar? Or do you know workarounds / solutions for this behaviour?

I was not able to reproduce anything like this with screen sharing on my Macbook Pro.