I0I - 2021-09-28

Getting same issue, also no details what causes and how to resolve. When trying to reset sync also bunch of errors occur.

Trying to Sync:
28-9-2021 11:31:41 Sync started
28-9-2021 11:17:45 Error: Execution of authentication request returned unexpected result: 404
28-9-2021 11:18:00 Error: Execution of authentication request returned unexpected result: 404
28-9-2021 11:22:16 Error: Execution of authentication request returned unexpected result: 404
28-9-2021 11:22:36 Error: Execution of authentication request returned unexpected result: 404
28-9-2021 11:25:52 Error: Execution of authentication request returned unexpected result: 404
28-9-2021 11:28:17 Error: Execution of authentication request returned unexpected result: 404
28-9-2021 11:31:41 Error: Execution of authentication request returned unexpected result: 404
28-9-2021 11:31:41 Sync failed
I have used the same Sync Profile name as in the previsous version 'Mod'. Cannot select the contact list in Outlook. Is this version picking the right one? Is the name of importance?