AttaBoyLuther DanTheManSWE ilsensa7 Davidz_
0xC000006D (The attempted logon is invalid) it's legit and it means that the user account you are using is member of any of the groups specified in the ms-DS-Never-Reveal-Group/Denial group defined into the RODC AzureADKerberos object => credential will be rejected.
If you collect a network trace you would also see a TGS-REQ for sname-string krbtgt and a response from your Domain Controller error-code: eRR-TGT-REVOKED confirming this behavior.
ms-DS-Reveal-OnDemand-Group attribute
Used with RODCs to define which users, computers, and groups are allowed to have their passwords cached on an RODC.
ms-DS-Never-Reveal-Group/Denial group
Used with RODCs to define which users, computers, and groups are not allowed to have their passwords cached on an RODC.
By default Domain admins, account operators, enterprise admins
Try with a standard Domain User and you will get this working obtaining a TGT.
A quick way to test this it's lock/unlock the client with the FIDO2 and then in cmd klist get host/%computername%
Then, with klist TGT you will see the TGT.
Michele Ferrari
Sr. Premier Field Engineer - Azure