How to stop unauthorized login attempts for my Microsoft account that keep pinging my Microsoft Authenticator app for the correct number?

I have seen online that other users have had the same problem as me. I found a good post about it with a neat answer (Link below); HOWEVER, it does not work for me. When I try to add another alias (new or existing), I get prompted with the message, "There's a temporary problem with the service. Please try again. If you continue to get this message, try again later.". I plan to wait it out and try again tomorrow and hopefully that works. If not, then I don't really know what to do. I think I know how the hacker(s) are doing it:

They know my email address and then are using, "Sign in another way" to select sending a number to my Microsoft Authenticator app. As long as I don't click the right number then they cannot hack me. I even have 2FA enabled but it doesn't allow me to setup requiring entering a password before getting to the authenticator app. Is there any other way to fix this? I would have replied with a comment to the answer in the link below, but the comments are now locked there so I had to make a new post about this.

Link: https://learn.microsoft.com/en-us/answers/questions/4686760/how-do-i-stop-hackers-from-trying-to-sign-into-my?source=docs