Unable to access httpbin with sidecar from sleep without sidecar


I was just testing 1.5.4 and doing mtls exercise. I’m unable to access httpbin service which has istio-proxy side car attached from a “sleep” pod without istio-proxy sidecar. If I try to access same “httpbin” service from “sleep” with istio-proxy sidecar, it works just fine.

How do I go about troubleshooting it? thanks in advance