Why explicit protocol setting cause traffic routing error?

1

I write a virtual service to test header based routing

apiVersion: networking.istio.io/v1beta1
kind: VirtualService
metadata:
  name: http-app
  namespace: default
spec:
  hosts:
    - http-app.default.svc.cluster.local
  http:
    - match:
        - headers:
            canary-token:
              exact: haha
      route:
        - destination:
            host: http-app.default.svc.cluster.local
            subset: canary
    - route:
        - destination:
            host: http-app.default.svc.cluster.local
            subset: stable

The traffic routing is right when service is

apiVersion: v1
kind: Service
metadata:
  name: http-app
  namespace: default
  labels:
    env: prod
spec:
  type: ClusterIP
  selector:
    app: http-app
  ports:
    - port: 3011
      targetPort: 3011

[2023-08-28T04:00:01.156Z] "GET /mesh HTTP/1.1" 200 - via_upstream - "-" 0 78 645 644 "192.168.65.4, 127.0.0.6" "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/116.0.0.0 Safari/537.36 Edg/116.0.1938.54" "24cb1d39-33f6-4e07-8ba5-fefc4c656498" "nginx-app.local" "10.1.13.85:3011" outbound|3011|canary|http-app.default.svc.cluster.local 10.1.13.93:44452 10.104.186.154:3011 127.0.0.6:0 - -

But when I explicit set protocol to http like this

  ports:
    - port: 3011
      targetPort: 3011
      appProtocol: http

or this

  ports:
    - name: http-app
      port: 3011
      targetPort: 3011

The traffic routing will be allow_any

[2023-08-28T11:23:10.344Z] "GET /mesh HTTP/1.1" 200 - via_upstream - "-" 0 78 652 652 "192.168.113.118,192.168.65.4, 127.0.0.6" "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/116.0.0.0 Safari/537.36 Edg/116.0.1938.54" "f54af48b-6f67-4f64-ba05-2d5d9215fd8c" "nginx-app.local" "10.104.186.154:3011" PassthroughCluster 10.1.13.93:38016 10.104.186.154:3011 127.0.0.6:0 - allow_any

what’t wrong here?