Ultimate Facebook Plugin Login issue

Hello, Ultimate Facebook plugin redirects sign in user to the blank page and displays ?wdfb_expand=true in the browser.
Not sure what could've happened, but It worked before and it still works with free plugin Facebook Login.
In case there is no easy fix to that issue how can I remove "Login with Facebook" button. It always displayed even if I uncheck "Allow users to connect using Facebook" and
"Allow single-click registration"

Thank you for your help