Can't connect to etcd via etcdctl

Question

I have deployed etcd server(3.5.0) as a container on Kubernetes and am able to access the /version and /metrics endpoints via the fqdn in HttpProxy on my local machine as below:

https://etcd.apps.domain.net/version
https://etcd.apps.domain.net/metrics

I am on windows platform. I am using etcdctl (3.5.0) which I have downloaded from here: https://github.com/etcd-io/etcd/releases/tag/v3.5.0 , to connect to the server as below:

etcdctl.exe --endpoints=https://etcd.apps.domain.net:443 endpoint health

But the client is not able to connect to the server and gives the below error:

{"level":"warn","ts":1650617630.997635,"logger":"client","caller":"v3/retry_interceptor.go:62","msg":"retrying of unary invoker failed","target":"etcd-endpoints://0xc00072c380/#initially=[https://etcd.apps.domain.net:443]","attempt":0,"error":"rpc error: code = Unavailable desc = error reading from server: EOF"}
{"level":"warn","ts":1650617632.298635,"logger":"client","caller":"v3/retry_interceptor.go:62","msg":"retrying of unary invoker failed","target":"etcd-endpoints://0xc00072c380/#initially=[https://etcd.apps.domain.net:443]","attempt":1,"error":"rpc error: code = Unavailable desc = error reading from server: EOF"}
{"level":"warn","ts":1650617633.598635,"logger":"client","caller":"v3/retry_interceptor.go:62","msg":"retrying of unary invoker failed","target":"etcd-endpoints://0xc00072c380/#initially=[https://etcd.apps.domain.net:443]","attempt":2,"error":"rpc error: code = Unavailable desc = error reading from server: EOF"}
{"level":"warn","ts":1650617634.607135,"logger":"client","caller":"v3/retry_interceptor.go:62","msg":"retrying of unary invoker failed","target":"etcd-endpoints://0xc00072c380/#initially=[https://etcd.apps.domain.net:443]","attempt":3,"error":"rpc error: code = DeadlineExceeded desc = context deadline exceeded"}
https://etcd.apps.domain.net:443 is unhealthy: failed to commit proposal: context deadline exceeded
Error: unhealthy cluster

Now I know the cluster is not unhealthy because I can access the version endpoint on my local machine : https://etcd.apps.domain.net/version. The output is:

{"etcdserver":"3.5.0","etcdcluster":"3.5.0"}

My kube deployment file is as below:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: etcd
  labels:
    app: etcd
spec:
  replicas: 1
  selector:
    matchLabels:
      app: etcd
  template:
    metadata:
      labels:
        app: etcd
    spec:
      securityContext:
        runAsUser: 999
        fsGroup: 999
      containers:
      - name: etcd
        image: <image path>
        imagePullPolicy: Always
        resources:
          limits:
            ephemeral-storage: 1000Mi
          requests:
            ephemeral-storage: 1000Mi
        ports:
        - containerPort: 2379
---
apiVersion: v1
kind: Service
metadata:
  name: etcd
  labels:
    app: etcd
spec:
  ports:
    - name: https
      port: 2379
      targetPort: 2379
      protocol: TCP
  selector:
    app: etcd
---
apiVersion: projectcontour.io/v1
kind: HTTPProxy
metadata:
  name: etcd
spec:
  virtualhost:
    fqdn: etcd.apps.domain.net
    tls:
      secretName: ingress-contour/ingress-contour-default-ssl-cert
  routes:
    - conditions:
        - prefix: /
      services:
        - name: etcd
          port: 2379
---
apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: etcd.allow-ingress
spec:
  podSelector:
    matchLabels:
      app: etcd
  ingress:
    - from:
        - namespaceSelector:
            matchLabels:
              namespace: ingress-contour
      ports:
        - protocol: TCP
          port: 2379

My docker image for etcd :

FROM artifactory/lrh:8.4-202109
RUN mkdir -p /app
RUN chown -R 999:999 /app
COPY tar /usr/bin/
COPY etcd-v3.5.0-linux-amd64.tar.gz /app/
RUN yum -y install gzip
RUN tar -xf /app/etcd-v3.5.0-linux-amd64.tar.gz -C /app --strip 1
ENV ETCD_DATA_DIR=/app
EXPOSE 2379
ENTRYPOINT ["/app/etcd", "-advertise-client-urls", "https://etcd.apps.domain.net:2379", "-listen-client-urls", "http://0.0.0.0:2379"]