Step one: flow routes through a SNIPPET action targeting https://edge-fra.london.aws.cxone.com:8443. REST Proxy throws a 502 Bad Gateway with ERR_SSL_PROTOCOL_ERROR. Step two: we’ve pinned the cert chain in the BYOC console, so it’s not a trust store issue. Debug output stops dead after the initial SYN packet. Studio runs 2.4.1 and the Edge node sits at 7.12.3. VPC peering is active, yet the proxy container keeps timing out during the handshake phase. outbound_proxy settings match the default template.