I have been pulling my hair out with trying to update contacts within a list using the bulk update method via API. We attempted to force the bulk import to process existing contacts by including an unchanged native/core field (last_name) that we fetched from each contact and sent back exactly as-is.
Payload included: email, existing last_name, and the cf: custom fields.
The API accepted the job (201 Created).
Activity completed quickly with percent_done: 100, error_count: 0.
None of the CF fields were updated
The only way we are getting this to work is update each record at a time and throttling to under 4 records a second. It takes a while for larger lists.
Has anyone been able to get this to work with the bulk update method?
