Istio 1.8 : Envoy external auth filter is not working

I am using envoy external auth filter in istio. It works version 1.6 and 1.7. But in version 1.8 it is not working anymore. I want to use version 1.8 but i could not manage to work with this version.

What should be problem ?

apiVersion: networking.istio.io/v1alpha3
kind: EnvoyFilter
metadata:
  name: authn-filter
  namespace: istio-system
spec:
  workloadSelector:
    labels:
      istio: ingressgateway
  configPatches:
    - applyTo: HTTP_FILTER
      match:
        context: GATEWAY
        listener:
          filterChain:
            filter:
              name: "envoy.http_connection_manager"
              subFilter:
                name: "envoy.router"
      patch:
        operation: INSERT_BEFORE
        value:
          name: envoy.ext_authz
          typed_config:
            "@type": type.googleapis.com/envoy.extensions.filters.http.ext_authz.v3.ExtAuthz
            clear_route_cache: true
            http_service:
              server_uri:
                uri: http://auth-http-service.default.svc.cluster.local
                cluster: outbound|3000||auth-http-service.default.svc.cluster.local
                timeout: 1.5s
              authorizationRequest:
                allowedHeaders:
                  patterns:
                    - exact: "cookie"
              authorizationResponse:
                allowedClientHeaders:
                  patterns:
                    - exact: "authorization"
                allowedUpstreamHeaders:
                  patterns:
                    - exact: "set-cookie"
                    - exact: "authorization"