Inside ...\Common\Identity , you may find the following subkeys and values (names vary by Office version and update channel).
If Office will not stay signed in, follow these steps to clear all cached identity data: Outlook Password prompt disappears quickly Inside
A DWORD value to enable/disable Modern Authentication (Azure Active Directory Authentication Library). Inside
If the above does not work, or the password box does not pop up, you might need to force legacy authentication: Inside
You likely need to modify this key if you encounter the following, particularly in shared device scenarios or RDS (Remote Desktop Services) environments: 1. Constant Credential Prompts / "Need Password"
This key serves four primary purposes:
