Two Factor Authentication with the same email address
Google Authenticator no handles this situation correctly, and this article is less useful than it once was.
Microsoft recently added two factor authentication. You should add this to your account. It’s a good thing.
I recently tried on my Android phone to scan the barcode, but it wasn’t working. My co-workers and I figured out that the Google accounts we already had setup on the Android authenticator app shared the same email address. Both Google and Microsoft were using that for their account name, so the second account wasn’t being added.
To get around this, I manually added the account and gave it a name other than my email address. I now have firstname.lastname@example.org“ for Google and "Microsoft” for Microsoft.