I had the same problem, and not even Microsoft knew how to help me. BUT when you open your outlook on your mac, you will see a toggle switch "New Outlook" click it to turn it on and re-open your outlook, and that should solve the problem, as it has solved mine. Good luck!
sheynab
Users receive reputation points by contributing quality content to the forums.
Posts include post and replies published on the forums.
Post authors can mark replies as Accepted to indicate successful solutions.
Apple Developer Forums admins can mark replies as Apple Recommended to indicate an approved solution
From
Honolulu, HI