As the questioner writes
In the advanced tab, Valid OAuth redirect URIs is set to: …
and I had the same problem (writing the redirect url into the wrong input field) I would like to highlight that
It’s NOT
Settings -> Advanced -> Share Redirect Whitelist
but
Facebook Login -> Settings -> Valid OAuth redirect URIs
It would have saved me 2 hours of trial and error.
You should also have it in mind that
www.example.com
is not the same as example.com
. Add both formats to the redirect URL.