This incident has been resolved.

We implemented a temporary fix: now we send a simpler, text receipt to all the customers.

Once Facebook fixes the bug, we'll return to sending the proper Receipt template.

The Facebook Messenger team is still investigating the issue, we are waiting to hear back from them.

Currently we cannot send the Messenger Receipt messages, due to a recent change in Facebook API behaviour.

At the moment we are waiting for the Facebook Messenger team's response and investigation.