I have essentially the same question. Trying to log into Power BI account requires 2-factor, asks for code, but can't get code from authenticator. Super frustrating loop.
Authenticator non-ending loop
Recently I had to factory reset my iphone but had not realized the Authenticator app needed 2 way verification re-established. Since that time, a well meaning fellow employee, attempted to reset my Microsoft password for my business account which we use for Azure. I have reset the password again and I get the codes from my email and phone but then it forces me to verify via Authenticator because I have 2 way authentication setup. But I cannot authenticate because I am unable to get the verification code from Authenticator even though my account is in there. I am able to generate codes, which are 8 digit but the sign in requires a 6 digit code. So it is a never ending loop of I can't log in to the account without verification and I can't complete the 2 step verification in Authenticator without generating a QR code in the account which I can't log in without verifying in Authenticator.
Even asking this question, I was only able to do so by logging into my personal account. Very frustrating and I cannot find any solutions. We are a small non-profit so I am the only administrator.