Faceebok integration not working

We have self-hosted, on-premises, newest version of RC. I want to turn on receiving messages from my page on FB. I have entered both API key and secret, logged into my FB account, selected the page, granted all rights, turned on, greenlit, bot nothing comes to me.

Do you have gauys any ideas what could be an obstacle here? I think configuration is fine, on the facebook side eveyrthing is fine also - I have another messaging app linked there and it receives messaes via facebook.

Something within RC itself? Something with our infrastructure? Port? Protocol? I am out of ideas.

Thank you for your time.