When I try to log in with my azure personal account, I am redirected to a different organization’s portal.

I have a Microsoft 365 Personal subscription and created an application in Azure (Entra ID) to access my mailbox using the Microsoft Graph API. I configured the app with OAuth 2.0 and granted Mail.ReadWrite permissions.

I was able to successfully obtain an access token, but when attempting to send an email, I consistently received a “User not authorized” error. After troubleshooting for a long time, I discovered that the user associated with the application was defined as an external user.

To resolve the authorization issue, I attempted to change the user to an internal (B2B) user. Immediately after making this change, Azure returned an error. Since then, I have been unable to sign in to my account at all.

When I try to log in with my personal account, I am redirected to a different organization’s portal. I have tried signing out, using an InPrivate/Incognito browser session, and clearing the browser cache, but the issue persists. I am now completely locked out of my account and cannot revert the user back to an external user.