The UID of a message changed unexpectedly. This typically indicates a server bug. Your program may not function properly after this.

Deleted the account in outlook. restarted Outlook, created a new account (different name than before). I let Outlook auto configure the new account. The autoconfig worked great, all 3500 messages were downloaded. I deleted some old messages from 2018 and they were marked as deleted in outlook.

The first sync generated the error message (uid error)and did not remove the deleted messages. Subsequent syncs do not remove deleted messages. And if purge the messages from Outlook they are not deleted either.