Locked out of Microsoft Partner Center by 2FA

We are unable to sign into our Microsoft Partner Center account with the account owner's email.

The account owner email:

Microsoft has also created some other user/email for us, though I am not sure why, and this is account is not the owner

When attempting to sign in with our correct email & password for the owner account, it asks for a 2FA code. But, there is no apparent way to set up 2FA with the Microsoft Authenticator App.

I was, however, able to set up 2FA for the account. When going through login, it gave me all the steps, including revealing a QR code, to link this account to the Microsoft Authenticator.

Now, in my Microsoft Authenticator app, I see both accounts - the #EXT# account, and the original owner account. But only the #EXT# account has 2FA set up. The owner account does not, and I can not set it up properly in any way, even though I am the creator and owner of this account and I have our username and password. The sign in flow simply never allows me to set it up, and I am in a loop of it asking for my 2FA code that I can not generate.

How can I set up 2FA properly for this account? I have been on hold with the data protection team for 4+ hours over the past 2 days with no luck.