SIP trunk registration failing with 408 timeout on ServiceNow webhook callback

No idea why this is happening, our SIP trunk registration is dropping with a 408 Request Timeout immediately after the Architect flow triggers a synchronous webhook to ServiceNow. The latency exceeds the 3000ms threshold. we are using Genesys Cloud v2023-09 and ServiceNow London Patch 3. the payload is small, just a JSON object with agent ID and call direction. any ideas on how to reduce the webhook response time or configure the timeout? thanks.