Can't login thus can't play the game

Hi.

Back when Halo MCC first released with Halo: Reach I created a new Microsoft account with an email address I’ll call adress A. I had no problem at the time if not for the fact that I didn’t like the username the game apparently gave me (I remember choosing one but whatever). I didn’t think much of it until now with the release of Combat Evolved. I wanted to change username for the multiplayer so I thought “I’ll just login with a different Microsoft account, maybe I missed something last time”.
So I log out, click “sign up”, enter my adress B and I’m told there’s already an account with this adress. Ok then I think, maybe I created one a long time ago. So I go back, hit “sign in” and enter my adress B. Thankfully I remembered the password and I’m getting signed in. But that’s where my problem begins. An error message tells me “Something went wrong, there is a problem with your Microsoft account. To fix this, sign in to account.live.com from a browser”

Alright no problems, this is an old account, it probably got locked. So I go the website, follow the steps to get it unlocked up until when they ask for my phone number to send me a code. The code never arrived. I try again, now I have to wait until tomorrow because of too many requests for the code… Alright then I think, screw my username I’ll go back to using my Adress A account. I start Halo MCC again, press a key, the “let’s get you sign in” thingy appears, I click next, and boom they automatically try to get me on my adress B account which is still locked… So now I’m stuck in this loop where I can’t connect to the account but it automatically tries to, and never lets me choose another account.

So I thought maybe there’s a way to clear user data so it forgets the last email used and asks me again for it…

I have the exact same problem!! Have you figured it out?