Azure B2C password reset using username

bwano I know this is an old question, but just in case it still helps you or anyone else who might read this 🙂

I was running into the same problem, and I finally figured out how to get self service password reset to work for username-based accounts. What I had to do is to select the B2C user, and add their e-mail address. However, not by clicking "edit properties", but by selecting "authentication methods" and entering the e-mail address over there!

I think this way B2C is able to find the link between the e-mail address used to start the password reset with (and receiving the code), and afterwards entering the related username for that account.