Istio Proxy blocking TCP Traffic

Networking
1

Hello Everyone,
Currently, we have a deployment file with an init container which test connectivity to the DB as per below:

- name: wait-database
          image: 'busybox:4.3.13'
          command:
            - sh
            - '-c'
            - >-
              until nc -w3 -z testdb.local 1521; do echo waiting for
              oracle; sleep 3; done;
          resources: {}
          terminationMessagePath: /dev/termination-log
          terminationMessagePolicy: File
          imagePullPolicy: IfNotPresent

A service entry has been created as per below:

apiVersion: networking.istio.io/v1alpha3
kind: ServiceEntry
metadata:
  name: external-oracle-db
spec:
  hosts:
    - testdb.local
  addresses:
    - 10.120.1.76/16
  ports:
    - name: tcp
      number: 1521
      protocol: tcp

Without the proxy running as a sidecar, the command executes successfully on init container but with the proxy running, it does not get executed. Is there any particular policy I need to run on the node.
Thanks.