Facebook has recently introduced a messaging policy which does not allow apps to send messages to customers 24 hours after they have messaged a page.
For example, if a customer messages a page on 8th March 2020 at 5:00 PM, they have until 5:00 PM 9th March 2020 to respond. After this window, they cannot send a response. Please note that this is a rolling window. If the customer sends another message at 5:30 PM, they have until 5:30 PM the next day to respond.
This change is in line with people’s expectations of faster responses from businesses. Please refer to Facebook's article for more details around this policy.
2. Using API
If you have multiple Facebook pages integrated with your Freshdesk and have separate groups that handle just DM tickets, you can use webhooks to send an automatic reply. This requires the addition of a new feature from our end. Please reach out to us at email@example.com if you would like to get this feature enabled.