Screenshare stops sharing after some minutes

### Steps to reproduce

1. Start a screenshare in a group call (on SPA)
2. Screenshare starts as normal and works for a few minutes
3. Notice after some time that the screenshare stops (silently)

### Outcome

#### What did you expect?

Screenshare runs until the user explicitly stops sharing.

#### What happened instead?

Screenshare stops on it's own, no feedback as to why.

### Operating system

Not sure (will check)

### Browser information

Not sure (will check)

### URL for webapp

call.element.io

### Will you send logs?

Yes