Can't Log in to Outlook

I woke up this morning to my Outlook account being logged out upon startup. Typing in the credentials, I was informed that the account doesn't exist. I checked my phone, I'm in the account - so that's not true to that extent.

I have Malwarebytes installed, and ran a full scan with zero issues. I went back in to the login page and tried logging in using my phone number (same account doesn't exist response), contacting Microsoft support via chat/phone/email - all which lead me right back to the login page - and we all know how far that got me... I basically spent 4 hours of my day going in a circle.

I've heard that maybe an 'alias' has been set up for my account. I didn't do it, and don't know how to remove it. I'm guessing I'd have to be logged in to do so. Any direction on this is greatly appreciated. Thanks, Shep

Maybe this is what is causing the problem:
Microsoft authentication issue hits Outlook, Skype, OneDrive, Xbox

I looked at that thread, but don't see a solution - maybe I just don't get it, though... And maybe it's still not sorted for Outlook.

If it's a MS problem affecting you i don't know what you can do other than wait for MS to fix it.
So far i've been lucky and not had problems logging in to MS/Outlook accounts.

I shall be patient. Thanks for chiming in, David.

You're welcome, i've spent hours trying to fix problems caused by vendors, and it is frustrating to learn it was their issue (not me).