Hi @HCarless,
You’re not missing anything. This is a known limitation with HubSpot’s native Facebook Pixel integration. Currently, HubSpot sends the external_id for both CAPI events, but does not include the event_id parameter. The event_id is what Facebook uses to de-duplicate events, so without it, you’ll see duplicate Lead events when both client and server events are triggered by the same form submission.
This issue has been raised by users since the feature’s beta, but as of now, HubSpot hasn’t updated its integration to support event_id for de-duplication.
If accurate reporting is important for you, you have a couple of options:
- Use a custom implementation of the Facebook Pixel and CAPI outside of HubSpot, where you can control and sync the event_id parameter yourself.
- Consider using a third-party integration or middleware that supports event_id mapping for both client and server events.
If you stick with the native HubSpot integration, unfortunately, there’s no built-in fix at the moment. I recommend upvoting or commenting on related HubSpot Ideas or threads to help push this feature request forward.
Let me know if you need tips on custom setup or tools that can help!