Hi All,
We have already noticed the issue you raised here, and we are sorry for the inconvenience caused.
Before involving our Escalation Support team to investigate this issue, I would like to confirm the following information with all of you:
1.Are you during the Office 365 Service Upgrade?
2.If you have completed the Service Upgrade, have you configured your Autodiscover and MX settings? Please refer to the article here to confirm this.
3.Is there any error code when you connect Outlook for Mac to Exchange Online? If yes, please provide it for us.
Thanks,
Jolin Qiao