Facebook Integration login problems


I have been getting reports from some of our members that they are unable to log in via the Facebook integration feature. Has something been changed on the Xenforo or Facebook side of things that we need to adjust from our site's side? I'm being told that there's some sort of redirecting loop followed by an error. Or is this something we need to take up with our hosting service? They are able to log in with their regular forum ID and password without any problems.

Thank you.
It's been working fine all along. I just started getting problem reports via our Facebook account from members the day before yesterday.