I had the same issue but managed to fix this.
You have to:
- Close Metagrid Pro, server and app
- Open System Settings app,
- click on “Privacy & Security” tab,
- Select “Accessibility”
- Metagrid must be already in the list. Remove Metagrid entirely by selecting it and clicking on the minus sign “-” bottom left. Close System Settings.
- Relaunch Metagrid. It will ask to “allow permission or else”.
- Reopen System settings and go back to “Accessibility”. Metagrid should reappears in the Accessibility list . If not, add it manually with the “+” sign.
- Close System Settings. Close Metagrid.
- Launch Metagrid, it should be fixed at this point. If not, repeat this whole process. I had to do it 3 times before it work. (something to do with Apple cache I think)
Good luck!
Tell us know if you manage to fix it too!