Another reason this will happen is if you are logged in as a test user from a different app than the one you are trying to sign in to. Facebook test users are app-specific.
Sign out of Facebook and back in with a test user from the correct app.
Another reason this will happen is if you are logged in as a test user from a different app than the one you are trying to sign in to. Facebook test users are app-specific.
Sign out of Facebook and back in with a test user from the correct app.