Predictive Routing 400 Error: Invalid Segment Payload in ServiceNow Data Action

Struggling to figure out why the Predictive Routing API returns a 400 Bad Request when triggered by a Genesys Cloud Data Action. The flow attempts to update a ServiceNow task with routing segment details. The endpoint /api/v2/analytics/predictiverouting/segments seems correct, but the payload validation fails. Here is the JSON being sent:

{
 "segmentId": "seg_123",
 "confidence": 0.85,
 "target": "sn_ticket"
}

Is the confidence field expecting a different format or scale?