Tenant to Tenant migration clearing settings from mobile apps

[Alis_Klar]

We have completed a tenant to tenant migration whilst keeping the UPN (username e-mail) the same.

 

We have MFA enabled on new Tenant but not old.

 

For some reason the authenticator app and outlook app are still trying to authenticate against the old Tenant and its failing.

 

Users can enrol them selves in MFA and log into 365 using PC no problem.  Its just on the mobile apps.

 

Using a browser on mobile also works ok.  How to you clear out the record of the old account as is persists even after removing Outlook and Authenticator apps.  Seems to affect Android and iOS the same way

 

Could the cause be bad DNS configuration or would validating the domain in 365 fail if there were DNS issues.

Edited October 2, 2025 by Alis_Klar

[Alis_Klar]

If the fix is to require re-registration of MFA?  This has worked in one case but not sure of exact order of events now.  Just pulling my hair out 💥

[Alis_Klar]

As suspected this is the error 

 

https://learn.microsoft.com/en-us/troubleshoot/entra/entra-id/app-integration/error-code-aadsts50020-user-account-identity-provider-does-not-exist

 

but don't know how to fix as there is no equivalent of incognito or delete browsing history with the Outlook app AFAIK.

[TLARWise]

Try this:

 

https://web.archive.org/web/20250208151825/https://care.osmosis.net/support/solutions/articles/36000537453-sign-in-issues-after-tenant-to-tenant-migration-ios

[Alis_Klar]

Wow! That is a find! Will try that out with a user who has the problem and post back my findings!