Api-server is filled with this error

W1019 11:42:03.627345 1 dispatcher.go:129] Failed calling webhook, failing open validation.istio.io: failed calling webhook “validation. istio. io”: Post “https://istiod.istio-system.svc:443/validate?timeout=30s”: dial tcp connect: no route to host
E1019 11:42:03.627365 1 dispatcher.go:130] failed calling webhook “validation.istio.io”: Post “https://istiod.istio-system.svc:443/validate?timeout=30s”: dial tcp connect: no route to host
I1019 11:42:03.629840 1 trace.go:205] Trace[858221563]: “Create” url:/apis/networking.istio.io/v1alpha3/namespaces/istio-system/gateways,user-agent:pilot-discovery/v0.0.0 (linux/amd64) kubernetes/$Format,client: (19-Oct-2020 11:42:00.558) (total time: 3071ms):
Trace[858221563]: —“Object stored in database” 3071ms (11:42:00.629)
Trace[858221563]: [3.07170988s] [3.07170988s] END

WHY this error am facing i have no clue.

Using Kubeadm in EC2 instances (xlarge) with security group ports open
-> sg ->

|Custom TCP|TCP|6784||Weave-net|
|Custom TCP|TCP|15017||Pilot discovery validation webhook|
|Custom TCP|TCP|32222||K8s-Dashboard|
|Custom TCP|TCP|31234||Kiali|
|Custom TCP|TCP|6443||-|
|Custom TCP|TCP|31233||-|
|Custom TCP|TCP|31231||Grafana|
|Custom TCP|TCP|8443||Metric-server|
|Custom TCP|TCP|31232||-|
|Custom TCP|TCP|10250||-|
|Custom TCP|TCP|15012||istiod-https-dns|

k8s version -> 1.19.2
istio version -> 1.7.2

istioctl version
1 error occurred:
* error port-forewarding into istiod-d7464f9db-vgk94 : an error on the server (“unknown”) has prevented the request from succeeding (get pods istiod-d7464f9db-vgk94:15014)

Please help on this.
Thank you
Mayank Gwal