Facebook Lead Ads Not Triggering Workflow — Please Investigate Webhook Delivery and Previous 403

Hello Pabbly Support Team,

My Facebook Lead Ads workflow is not triggering when new leads are submitted. Please investigate the webhook delivery and backend processing for the specific workflow below.

Workflow and lead details

• Workflow URL:
  https://connect.pabbly.com/v2/app/workflow/share/WBBWZFMEBmUCSAdtAWQFIgkdUVUCWAk0ARgCEAYJVi5WG1IpDE0IYgBMByUCQVc2BE0FbwdbADwAFAAEAVcFdgEbAQNWVVQuUB0FflYbDD9YBlZ-UzI#
• Form ID: 28495443176778988
• Page ID: Not yet confirmed.
• Missing Lead ID: Not yet confirmed. I initially recorded the same value as the Form ID, so please do not treat it as a verified Lead ID.
• Latest submission time: September 28, 2026, at 9:18 AM KST (UTC+9), equivalent to September 28, 2026, at 00:18 UTC.

Issue and troubleshooting completed

• Earlier test submissions successfully triggered the workflow, but leads submitted through the live ads did not.

• My latest manual submission through the form’s test option also did not trigger the workflow.

• Other Facebook Lead Ads workflows are working normally, although I have not verified whether they use the same page, form, or connection.

• I have recreated the affected workflow and recreated the instant form multiple times, but the issue persists.

• I also found a previous failure in the Facebook Lead Ads step with this message:

  “Failed (403): The response received from the Facebook Lead Ads app is shown below.”

I do not yet have the detailed response body for that historical error. Please check whether it is related to the current issue.

Please investigate the following points

1. Webhook receipt: Did Pabbly receive a Meta leadgen webhook for this form around the submission time above? Please check the incoming webhook logs, rather than relying only on the visible Task History.

2. Processing after receipt: If the webhook was received, why did it not trigger this workflow? Please check workflow routing, duplicate detection, event exclusion, processing queues, and any internal errors.

3. Lead retrieval and the 403 error: Did Pabbly attempt to retrieve the lead details from Meta? If that request failed, please provide the HTTP status and Meta error details, including message, code, error_subcode, and fbtrace_id, where available. Please distinguish a webhook delivery failure from a lead-detail retrieval failure.

4. Subscription and access: If no webhook was received, please verify the page’s subscription to your app for leadgen events and the relevant connection and Leads Access permissions. Please identify the specific missing or invalid setting, if any.

5. Required identifiers: Can you identify the associated Page ID and missing Lead ID from the workflow and timestamp? If not, please give me the exact steps to obtain them so that you can trace this submission.

6. Resolution and verification: Please provide the root cause and a targeted fix. Since recreating the workflow and form has not resolved the issue, please investigate the existing connection and server logs before recommending another rebuild. Please also explain how we can verify the fix using a new submission without manually capturing a test response in the workflow builder.

If a backend investigation is required, please escalate this ticket to your technical team. A successful sample capture alone would not confirm that automatic processing of live advertising leads has been restored.

If any account access or configuration changes are needed, please specify them before proceeding.

Thank you.