The fix implemented by Facebook was not successful. Another issue has been opened and one of Facebook's Engineer has been assigned to the issue: https://developers.facebook.com/support/bugs/393441492018560/

Facebook has implemented a fix and has closed the issue: https://developers.facebook.com/support/bugs/1248094478904310/
We are monitoring the results.

We are continuing to work on a fix for this issue.

Facebook is not sending the messages' attachments when notifying us about new Messenger messages. The bug is known by Facebook and one of their Engineer has been assigned to the issue: https://developers.facebook.com/support/bugs/1248094478904310/