Empty subject in x-forwarded-client-cert

I am trying to get my client certificate common name in headers of my service, but unfortunately I am getting empty string for subject.

X-Forwarded-Client-Cert: By=spiffe://cluster.local/ns/default/sa/default;Hash=afb15b2fa11e07b572fb8cc549a07a71b169bdd818199ab1c2ad90f6f05fb2aa;Subject="";URI=spiffe://cluster.local/ns/istio-system/sa/istio-ingressgateway-service-account

Could you let me know do I need to use any EnvoyFilter or it is default behaviour? I tried with Istio 1.3 version.

Empty subject means envoy is able to forward the information, but it is not able to fetch client certificate details?