kubernetes ingress returns 400 error for upstream http2 grpc application

Question

I've created the ingress with below yaml

 apiVersion: networking.k8s.io/v1
  kind: Ingress
  metadata:
    annotations:
      nginx.ingress.kubernetes.io/backend-protocol: "GRPCS"
      nginx.ingress.kubernetes.io/ssl-redirect: "true"
      kubernetes.io/ingress.class: public-iks-k8s-nginx
    labels:
       app: "spring-gateway-fybrik-latha-gateway"
    name: fybrik-cp-proxy-ingress
    namespace: fybrik-latha-gateway
  spec:
    rules:
    - host: <upstreaM-hostname>
      http:
        paths:
        - backend:
            service:
              name: spring-gateway
              port:
                number: 443
          path: /
          pathType: Prefix


    tls:
    - hosts:
      - <upstreaM-hostname>
      secretName: none

If I directly call my grpc http2 application, it works as expected. But when I call ingress url, it throws gRPC returned internal error, with message: Received http2 header with status: 400 error and I don't see any msg logged in my grpc application.