Running showcerts command in sidecar and get error

I run this command to validate certs in sidecar:

kubectl exec httpd-v1 -c istio-proxy -n default — openssl s_client -showcerts -connect web-service:80

Get error:

Unable to connect to the server: dial tcp: lookup howcerts on 10.142.50.2:53 server misbehaving

Trying to get mTLS working for many services which fail once STRICT is enabled in namespace and services are deployed.