I am using /contacts/v1/contact/createOrUpdate/email/:contact_email to update contacts regularly. Occasionally, I get a response with an error, but there is no indication of what the error was caused by:
I have read HubSpot responses to others with similar errors that suggest that the problem is invalid JSON being POSTed. However I can run the exact same update, using the same email address and POST body, and it will succeed.
This is particularly troubling because we are working towards using the bulk API which means we would have 100 updates randomly failing instead of just 1.
How can I find out what is causing this and get it resolved?