Graph for Ambient ns is not generated correctly when the traffic is not generated throw a Gateway

[josunect]

Describe the bug

The graph for an Ambient namespace is not generated correctly when the traffic is not generated throw a Gateway.
It depends where the traffic was originated, for some reason the total bytes are 0 for some of the istio_tcp_received_bytes_total and istio_tcp_sent_bytes_total

sum(rate(istio_tcp_sent_bytes_total)) Is 0 for some workloads.

sum(rate(istio_tcp_received_bytes_total{reporter="destination",destination_workload_namespace="default"} [30600s])) by (source_cluster,source_workload_namespace,source_workload,source_canonical_service,source_canonical_revision,destination_cluster,destination_service_namespace,destination_service,destination_service_name,destination_workload_namespace,destination_workload,destination_canonical_service,destination_canonical_revision,response_flags)

Expected Behavior

See the whole graphic:

What are the steps to reproduce this bug?

1. Create a kind cluster (Also minikube would be valid)

kind create cluster --config=- <<EOF
kind: Cluster
apiVersion: kind.x-k8s.io/v1alpha4
name: ambient
nodes:
- role: control-plane
- role: worker
- role: worker
EOF

2. Install istio Ambient:
   istio/install-istio-via-istioctl.sh -c kubectl -cp ambient
3. Install bookinfo (With no traffic generation to see how the Telemetry changes) and add to mesh (Run this commands from the Istio dir):

kubectl apply -f samples/bookinfo/platform/kube/bookinfo.yaml
kubectl apply -f samples/sleep/sleep.yaml
kubectl apply -f samples/sleep/notsleep.yaml
kubectl apply -f samples/bookinfo/networking/bookinfo-gateway.yaml
kubectl label namespace default istio.io/dataplane-mode=ambient

Generate some traffic:

kubectl exec deploy/sleep -- curl -s http://productpage:9080/ | grep -o "<title>.*</title>"
kubectl exec deploy/notsleep -- curl -s http://productpage:9080/ | grep -o "<title>.*</title>"

See the graphic:

Send some traffic throw the gateway:

export GATEWAY_HOST=istio-ingressgateway.istio-system
export GATEWAY_SERVICE_ACCOUNT=ns/istio-system/sa/istio-ingressgateway-service-account

kubectl exec deploy/sleep -- curl -s "http://$GATEWAY_HOST/productpage" | grep -o "<title>.*</title>"

See the graph:

Environment

Learn about how to determine versions here.

• Kiali version: 1.79
• Istio version: 1.21
• Kubernetes impl:
• Kubernetes version:
• Other notable environmental factors: Ambient profile

[josunect]

But, this is really the same behavior with sidecars: