Welcome to Q&A forum ~
Could you please test Office online apps? (Please note, Office Online requires OneDrive to store files, but using OneDrive in some regions requires a VPN connection.)
Such as Word online, you can go to Insert tab > Add-ins group, click Add-ins button, and then check this issue again.
- I also suggest you sign out your accout from Office apps, make sure all Office apps are closed.
- Then go to
Finder > Go > Utilities > Keychain Access.
In Keychain Access, select the "Passwords" category on the left, find the crendentials related to Office and remove it.
Go back to Office apps, sign your account back to have a check.
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.