When screen sharing, clicking share sound mutes everything for sharer and viewer

[ditto]

I was screen sharing one day, we had the show paused for a little bit, when we resumed, there was no sound in my system or the person watching system. Only occurs when I tick the "share sound" button. No sound is shared at all. Worked fine for many months before. As soon as I click share sound, it mutes everything for everyone. Help? Have tried uninstalling and installing, on and off screen share audio. The issue is sharing sound.