Hi Steve,
In order to narrow down the issue, I would like to collect the following information with you:
1. How many users are affected by this issue?
2. Could you please try to create a new identity to check this issue?
3. Have you tried to check this issue via a different PC?
4. Could you please try to troubleshoot this issue via Office 365 mailbox like user@domain.onmicrosoft.com or different user account?
5. Have you tried to contact our dedicated Microsoft community Outlook for Mac support?
Your patience and cooperation are highly appreciated.
Best regards,
Shyamal
