Architect Web Chat Trigger 400 on ServiceNow MID Server

Could someone clarify why the Genesys Cloud Architect flow fails with a 400 Bad Request when attempting to POST webchat_metadata to ServiceNow via the MID Server REST endpoint? The payload validates in Postman, but the Data Action fails immediately upon execution.

“Ensure the HTTP request method matches the target API specification. Genesys Cloud Data Actions support GET, POST, and PATCH methods for external integrations.”

The integration relies on the conversation_webchat_start trigger, and the JSON structure aligns perfectly with the ServiceNow incident table schema.