Edge BYOC Webhook 403 Forbidden on ServiceNow Incident Creation

Encountering a 403 Forbidden error when the Genesys Cloud Edge BYOC instance triggers a webhook to our ServiceNow instance for automated ticket creation. The standard cloud environment works, but the edge deployment fails consistently.

webhook:
 url: https://instance.service-now.com/api/now/table/incident
 headers:
 Authorization: Basic <base64_creds>
 Content-Type: application/json

Verified credentials are correct. Is the Edge outbound proxy misconfigured or blocking the request?