I am able to login my user with their username or email. But when they login or signup using Google or Facebook, they can only login that way using that information and cannot login using their username/email or password. And vice versa (users that signup without going through Google or Facebook initally cannot login in that way using their email account)
Adding social logins to email/password accounts (or adding add’l social logins and/or email/password to accounts that don’t already use them) was recently discussed here:
See Gaby’s response, which points to the documentation for this. (In short, when a user is logged in via whatever method they use, if you present them an interface to login via another technique, that login method will be added as a way they can log in. In the case of adding an email/password combination to a user who currently logs in with an Oauth social login, it’s a little different – you execute the “Reset Password” action on them and they’ll get sent a password reset email which allows them to create a new password. At that point, they now also have an email/password as a way to login.)