Hi Mendania
Thank you for using the QandA platform.
I’m sorry to hear that you're having trouble switching to your other tenant due to issues with the Microsoft Authenticator app. Losing access to the authenticator app can indeed prevent you from switching tenants or deleting one, especially if Multi-Factor Authentication (MFA) is enforced.
If you previously backed up the Microsoft Authenticator to iCloud or Google Drive, you may be able to recover your account by following the steps outlined in the Microsoft documentation: https://support.microsoft.com/en-us/account-billing/restore-account-credentials-from-microsoft-authenticator-ce53096e-1e1c-4840-9e32-1618bc33cd43.
If you cannot access the Authenticator app and you’re the only admin in the tenant, you will need to contact Microsoft Support for assistance with account recovery.
Regarding tenant deletion, please ensure you meet the following prerequisites before proceeding: https://learn.microsoft.com/en-us/entra/identity/users/directory-delete-howto.
You can mark it 'Accept Answer' and 'Upvote' if this helped you
Regards,
Obinna