Can't log in to xbox live, asking for a different email address

When clicking xbox log in it asks for your password and email, however when I get to the email part it says “email is already a Microsoft account. Please try a different email.”

Really confused on this promt. I only have one profile and it is still active, I play Halo Wars 2 all the time and even just recently updated my profile and password. Why is telling me to add a new email? All other live games just let me log in.