Unable to sign in either via browser or via the windows app

Background
I am a guest collaborator to multiple domains.  My firm is a small firm that uses Google internally but we often collaborate with larger firms or clients whose organizations use teams and have invited us to join their teams projects.  I personally created my Microsoft user account, originally to access SharePoint resources and now to access Teams resources.

The Problem

1. I go to sign in (making sure to select that this is a personal account) and I type in my email address and password.
2. It tells me the password is wrong (I know it isn't) so I opt to change the password.
3. I successfully change the password after receiving a verification code in my email.
4. It prompts me to sign in again using my new password.
5. It tells me the password is wrong (I know it isn't, I just changed it) so I opt to change the password, again.
6. And so on and so forth in a loop.

This exact scenario occurs both in browser and in the windows desktop app.

After an hour of this eventually the desktop app finally let me in but I don't know why.

Frustrated and Confused

Why would there ever be a condition where Microsoft would create for me two separate accounts using the exact same email address (and make it impossible to tell which is which) (screenshot below)?

Google isn't great either but at least my collaborators and I can sign in.