registrant_transfer_required
Registrant transfer required. The HTTP status depends on the call.
The contact update changes the registrant's identity number, which needs a holder change that could not be completed automatically. Nothing was saved.
What to do
To update other contact details, send the registrant’s current identity number unchanged. To change the holder, check the new holder’s details or contact support with the requestId.
Branch on code, not on title or detail. When you contact support about it, include the requestId. More in Errors and retries.