I am seeing the same issue.  I have confirmed the custom field exists in the "contact_custom_fields" API call response with "name": "points".  I am providing a "cf:points" value in the Bulk JSON upload alongside fields like "first_name", "last_name" which are being updated.  The "cf:points" field is not being set on the contact.  The /contact/XXX does not list any custom fields associated with the contact and the "updated_at" field has not changed. ... View more