Webhook 400 on Genesys Messaging to ServiceNow Integration

Looking for advice on a 400 Bad Request returned by ServiceNow when processing a Genesys Cloud messaging webhook payload.

The Architect flow sends a JSON body via Data Action to /api/now/table/incident. The payload validates in Postman but fails in production.

{"error":{"message":"Invalid column value","cause":"JSON parse error"}}

Any ideas on why the schema validation is failing specifically for the u_genesis_channel field?