@craigk,
You may need to grant permissions to the site to use your camera/mic and/or record video before you’re able to screen share. Additionally, Fingerprinting protection may be blocking the site from reading your screen. Try keeping your Shields panel up, but change the Fingerprinting control to All Fingerprinting allowed and see if this helps.
@rainevi,
Can you confirm in your OS System preferences that Brave has permissions to everything necessary, such a screen recording – you may need to allow Full disk access but I’m not entirely sure.
Try opening (in your OS) Finder, go to Security & Privacy --> Privacy
@craigk I had this same issue recently on windows. The issue was the hangouts components for screen sharing was turned off. As soon as i switched it on, worked like a charm! Hope this helps!
brave://settings/extensions -> Hangouts – Uses Hangouts component to enable screen sharing and other features in the browser.