Cannot authenticate with E-mail when logging into Microsoft Authenticator(iOS).

I am locked out of Microsoft Authenticator and cannot log in using alternative method.

I have lost access to my Microsoft Authenticator account when my mobile device (iOS) got blicked.
I have bought a new phone and migrated (recovered) to find that I have lost access to it.

When I try to login to my account in the app, it asks for authenticator authorization.
Since I don't have access, I proceed with "I don't have access to my Microsoft Authenticator app" option, which brings me to alternative authentication method, as shown in the image below.

The problem is, that I cannot authenticate using my alternative E-mail account.
The prompt asks for "the last 4 digits of phone number", where I think it should be asking for the full E-mail address. The textbox only accepts 4 charactors so I enter "e.jp" and sent it to get an error that says "There's a temporary problem with the service. Please try again. If you continue to get this message, try again later."

I have waited 2-3 weeks and tried again to get the same error. (Maybe not the same but essentially similar that tells me to wait it out.)

The SMS authorization seems to work, but the process asks for both methods because I have 2FA set up.

I could proceed with "I don't have any of those" option but I am unsure about that since I haven't lost access to them and not willing to give them up.

I have re-installed the Microsoft Authenticator app on my iOS but the situation didn't change.

Do you know how to authenticate with E-mail, when it asks for phone number?
I still have access to my account in my windows computer and browser but kinda worried that I might locked out of it too.