This may help the sharing issue: Chrome/ Google Meet settings after update
Due to an update on google meet or chrome, sharing of windows or screens has been disabled and so to enable it back on, follow the below steps.
- On Mac go to Settings —> Security & Privacy
- Click Screen Recording
- Uncheck/Deselect Google Chrome if already checked
- Recheck/Select Google
- Relaunch Chrome when prompted and it should work