Facebook login error: domain not listed in APP???

Hello,
I just noticed that when trying to logn/rgister using the facebook button I receive this error message from facebook

USER wrote: Impossibile caricare l'URL: Il dominio di questo URL non è incluso nei domini dell'app. Per poter caricare questo URL, aggiungi tutti i domini e i sottodomini della tua app al campo Domini app nelle tue impostazioni app.

it basically says "the domain of this URL is not included in the app domains and you need to add it..."

I checked my APP settings in both JFB Connect and Facebook, and the domain accademiainfinita.it is there. I've also ran autotune and everything is fine.

What could be causing this? Login with Google is working fine.

You may test here accademiainfinita.it by clicking on the "Accedi" blue button on the right handside of the site header

Joomla: 3.8.8
JFBConnect: 7.2.6

Thank you!