Thread owner change by API

Hey everyone,

I’m trying to change the owner of an email thread using the Pipedrive API endpoint:

PUT /mailbox/mailThreads/{id}

I included {"owner_id": 21945692} in the request body, but it doesn’t seem to work. The response says success:

{
“success”: true,
“statusCode”: 2000,
“extendedStatusCode”: 2000,
“statusText”: “Success”
}

However, the owner of the thread doesn’t actually change. I also noticed that the API docs don’t mention owner_id as an updatable field, only things like deal_id or shared_flag.

Has anyone managed to change the email thread owner through the API? Or is there another way to do this?