That article is the best and only resource we have at this time, but I’m happy to investigate further and submit feedback to the team which maintains the Knowledge Base.
Could you share links to a few contact records showing the changeSourceCONTACTS? Please specify which properties you’re looking at.
In that case, the CONTACTS change source must be a holdover from when HubSpot didn’t truly have a CRM — it was just the “contacts tool.”
I’ll pass the feedback to the Knowledge Base team. Thanks!
For others viewing this topic, the CONTACTS and CRM_UI change sources can be similar in that they both reflect manual user edits, however the CRM_UI umbrella also includes automated changes.