ServiceNow MID Server rejecting Digital Channel webhook with 403 Signature Mismatch

  • Genesys Cloud EU-West
  • ServiceNow Madrid 13.1
  • MID Server v2.3
  • Data Action: Create Incident from Messaging Session

Can anyone clarify why the signature validation fails on the inbound webhook for digital channels? The payload arrives at the MID server, but the script include returns a 403 Forbidden due to an invalid HMAC. The secret key matches the Genesys configuration exactly. Is there a known issue with how the body is encoded for messaging events compared to voice?