ServiceNow REST API 400 Error on Transcript Payload via Data Action

Having some issues getting my configuration to work… The Genesys Cloud Data Action triggers successfully, but the ServiceNow MID server returns a 400 Bad Request when processing the JSON payload from a digital channel transcript ingestion.

The payload structure matches the REST message definition exactly, yet the error log indicates a missing mandatory field for ‘sys_id’ during creation. Has anyone seen this specific validation failure in recent patches?