We've been able to resolve the issue, so Facebook Comments growth tool should be working as expected now. We recommend creating a new Comments widget for posts you wish to use with the tool to make sure everything works smoothly.
We'll be monitoring the results for some time before closing this incident.
Posted about 1 year ago. May 14, 2018 - 03:47 PDT
Due to recent Facebook API changes, Comments widget may be working incorrectly for a portion of users: we've received multiple reports that the Opt-In Message is not triggered when users provide replies to the Auto-response message.
Our dev team is currently looking into this issue - we will update this incident with further information.