Windows 10: Microsoft account login server has detected too many repeated authentication attempts

I have been trying to fix an issue for a friend of mine he keeps getting an error stating that "Microsoft account login server has detected too many repeated authentication attempts". We have tried using his account on multiple computers as well as multiple browsers. He is still getting the same error message. He is able to reset the password and access the account email. However after clearing the cache, cookies, and temp files on Fire Fox, Edge and Chrome he is still unable to access his account.

:)

 

The Microsoft account login server has detected too many repeated authentication attempts?

The Microsoft account login server has detected too many repeated authentication attempts?

 

The Microsoft account login server has detected too many repeated authentication attempts. Please wait a moment and try again.- I cannot sign into my account

I cannot sign into my account again - The Microsoft account login server has detected too many repeated authentication attempts. Please wait
a moment and try again. Someone help!!!

 

Windows Microsoft account authentication

I have a valid Microsoft account and a Windows 10 PC with Hello/PIN account login enabled. I also have the Microsoft Authenticator app installed on an iPhone and configured for the Microsoft account. Additionally, I have two step authentication configured
for the Microsoft account. With all of that said, I have become very exasperated while trying to unravel the various authentication paths (and their security implications) through this multi level login security scheme. I find the associated account security
documentation to be woefully inadequate. Thus, I would like to pose the following list of questions for starters.

1. Does Windows Hello/PIN amount to a two step verification login procedure for my Microsoft account?

2. Does approving a Microsoft Authenticator login attempt (without two step verification explicitly set up)

amount to a two step verification login procedure for my Microsoft account?

3. Does approving a Microsoft Authenticator login attempt (with two step verification explicitly set up)

amount to a two step verification login procedure for my Microsoft account?

4. If answers to both 2 and 3 are yes, then what does explicit set up of two step authentication do?

5. Does a coherent, comprehensive document explaining Microsoft account security configuration exist somewhere?

6. If the answer to 5 is yes, wherer is it?

Thanks in advance.