This article describes an issue where attempting to sign in via Microsoft O365 (Office 365) results in a redirection to Microsoft Authenticator, bypassing the Okta login process. Its purpose is to describe why this issue occurs. 

• Microsoft Office 365
• Sign Sign-On (SSO)
• Microsoft Authenticator

This issue is caused by a Microsoft configuration that defaults to the Microsoft Authenticator for sign-in.

To ensure Microsoft Entra ID is not forcing a default sign-in method, please check the user's authentication method settings:

1. Navigate to the Microsoft Entra admin center.
2. Go to Identity > Users.
3. Select the user.
4. Click on Authentication methods.
5. Verify that the Default sign-in method shows No default.

NOTE: If assistance is required to change this configuration, please reach out to Microsoft support, as this is a Microsoft Entra ID setting.