Istio Task: Collecting Metrics for TCP services

We didn't get the expected "istio_mongo_received_bytes" metric from Prometheus Dashboard after following the Istio doc steps.
This issue also happened in maistra-0-7-0 OCP 3.11.

Build: istio maistra-0-8-0
Environment: OCP 3.11
OCP console: https://tmor2-master.bc.jonqe.lab.eng.bos.redhat.com:8443/console/catalog

Test steps: https://preliminary.istio.io/docs/tasks/telemetry/tcp-metrics/
Results:
There is no "istio_mongo_received_bytes" metric from Prometheus Dashboard after following the Istio doc steps.