When sharing a window my share is now saying "Paused", but cannot restart

So a few days ago I was able to share any window happily. Now I get a screen share is paused. I try to restart/resume the share, but it has no effect. However if the window in in front of the zoom window and I share, it's fine. It was okay till a few days ago.

Admittedly I have downloaded a few programs for my new job such as a screen recorder Flashback Pro. I have rebooted a few times, but same problem.

Any ideas?

Thanks,

Gordon