I'm having a problem very similar to these two:
We have an integration creating timeline events based on given email addresses. The endpoint is returning 204, contacts are being created if they don't exist, and the timeline events are created in the sense that they are populating a list based on the event properties (https://app.hubspot.com/lists/1570479/list/1516).
Yet, the timeline events are not appearing for all the contacts, only for some of them. I've checked that the filters are available, and the timestamps should be correct.
Doesn't work: https://app.hubspot.com/contacts/1570479/contact/66162863/
App ID: 33185
Event type ID: 17080
Portal ID: 1570479
The UI endpoint for the first contact is returning the event payload, but for the second contact the payload is empty, returning just this:
Can you shed any light on what's happening here? Is the contact not somehow associated with the timeline event?
Also, debugging things like these is a strong vote for the ability to being delete timeline events, to try and fix this sort of behaviour (https://integrate.hubspot.com/t/delete-timeline-event-through-api/2654). Adding that verb would also give some sense of security when testing integrations (as now I have to do this in a sandbox environment and hope everything goes smoothly when migrating to production, meaning I have two integration apps created, two event types etc.).
Another improvement for the timeline API would be getting a response body on event creation. This could at its simplest have the visitor ID of the contact, and possibly an acknowledgement if the contact was newly created (or not). Understandably I'm having a bit of a hard time trusting the 204 right now with the UI issues, so being able to see timeline events on engagements API, or some separate GET endpoint for created timeline events wouldn't hurt either.
Thanks in advance!