Persistent IMAP OAuth authentication failure (AADSTS7000 / User is authenticated but not connected) on Outlook personal accounts in FairEmail

Hello,

​I am experiencing a persistent authentication issue with my personal Microsoft Outlook account ([email protected]) in FairEmail, and I've exhausted standard troubleshooting steps.

Symptoms:

When trying to set up or refresh the account, the OAuth browser sign-in completes successfully (my identity is verified), but the IMAP connection immediately fails with errors on the backend. Depending on the configuration method, I either get an expired token error (AADSTS7000) or User is authenticated but not connected.

What I have already tested & ruled out:

​1. Device Settings: Verified that device date, time, and time zone are correctly set to automatic and fully synchronized with the network.

​2. App Versions: Tested both the Google Play Store version and the GitHub release, and performed clean reinstalls of the app.

​3. OAuth Providers: Tried authenticating through all available Microsoft profiles in FairEmail:

​Outlook/Office 365 (OAuth)

​Outlook/Hotmail/Live (OAuth)

​Office 365 (alt) (OAuth)

​For the first three methods, the browser login succeeds, but the backend IMAP session is rejected with the exact same error screenshot attached.

​4. App Passwords / Basic Auth: Tested legacy IMAP configuration using an App Password, which resulted in a No login methods supported! error (expected, as Microsoft has deprecated basic auth).

​5. Account Permissions & Server Settings: Cleared app data, revoked FairEmail consent tokens from my Microsoft account (account.live.com/consent), and ensured that IMAP access (Let devices and apps use POP/IMAP) is explicitly enabled in Outlook.com settings.

Despite all of this, the IMAP layer on Microsoft's end consistently drops the session right after a successful OAuth handshake. Has anyone encountered this or found a workaround?

Attached are my current app error logs and device date/time settings.