Outbound Campaign API 400 on Bulk Contact Import

No idea why this is happening, the POST /api/v2/outbound/contacts endpoint returns a 400 Bad Request when importing 5000 records via JMeter. The payload matches the schema in Genesys Docs. Error message says ‘invalid contact status’ but the status field is set to ‘NEW’. Why is the batch failing at scale?

Have you tried verifying that the contact list ID in the payload actually exists and is active in the target organization? The invalid contact status error often masks a missing or inactive list reference rather than a problem with the individual contact’s status field.

Requirement Value
List Status ACTIVE
List Type OUTBOUND
Contact Status NEW