I'm experiencing a very weird issue with the Firebase Auth using Facebook. A month ago I've created a test user in Facebook to log in with like I always do, when I try to use it now, I get this error:
Error: An account already exists with the same email address but different sign-in credentials. Sign in using a provider associated with this email address.
I've seen this error before when people move from Facebook to Google with the same email. HOWEVER, this is not the case. This dummy Facebook user is totally not linked to a Google account. I can also find it's email address back in the Firebase console where it is still marked as Facebook:
This issue first appeared in the same timeframe as an upgrade of the Facebook plugin and SDK. I've however retested this account now on the old plugin and SDK versions and the issue remains, so this seems to be a coincidence.
Other accounts seem to work but we had a similar issue in our production environment which we now think could have been the same. This gives us the opportunity to fully debug this one.
Extra information: The (web)app runs on Angular (Ionic cordova). We are using the firebase.auth.FacebookAuthProvider, the error appears on both the Cordova (firebase.auth().signInWithCredential) as web (afAuth.auth.signInWithPopup) version. The network calls to Facebook and Googleapis seem to be ok and return the correct identity (see screenshot 2), it seems as if the Firebase package is incorrectly giving this error.
Console error:
Firebase Identitytoolkit Network response:
