Hello,

We are currently experiencing an issue where the messages Webhook does not get received for users who have not sent a message once via GraphAPI on a specific page.

Specifically, the issue is as follows:

1). User A sends a message to the Facebook page → Webhook is not received 2). Send a message to User A via GraphAPI 3). User A sends a message to the Facebook page → Webhook starts being received

This is the first time we have encountered such behavior. Where can we configure the settings for the messages Webhook?

The token permissions and subscribed_apps settings are as follows. Thank you for your assistance.

Scopes  pages_show_list, pages_messaging, pages_read_engagement, pages_manage_metadata, public_profile

"data": [
    {
      ...,
      "subscribed_fields": [
        "messages"
      ]
    }
  ]