An error occurred while saving the commentCharles T commented
I'm logged into teams from my company.
I tried to add Azure DevOps.
It asked me to sign in, so I gave it my "firstname.lastname@example.org" email.
It signed me in... but apparently to the Microsoft account directory as it never took me to my corporate login page like O365 / Teams usually do.
When I tried to complete the sign-in, it gave me the same complaint as above.