unable to reach to my gke pods using internal loadbalancer in gcp through port 8080

Question

I have created a nodeport service for my tomcat app which is working on port 8080 using a yaml file , I have also created an internal loadbalancer in GCP and using this internal LB frontend static ip:port I want reach to my gke pods , but some how I am not able to.

I am suspecting that backend of the internal loadbalancer doesn't picking port 8080 , also I guess the backend of internal LB doesn't support named port in zonal network endpoint group

here is the service file for google kubernetes engine :-

apiVersion: v1
kind: Service
metadata:
  name: stage-validation-service
  namespace: stage-api
  annotations:
    cloud.google.com/app-protocols: '{"stage-validationapi-port":"TCP"}'
    cloud.google.com/neg: '{"exposed_ports": {"8080":{"name": "validationapi-neg"}}}'
spec:
  ports:
  - name : stage-validationapi-port
    port: 8080
    targetPort: 8080
  selector:
    stage-api: stage-validation-api 
  type: NodePort

Note :- when I hit gke podip:8080 I am able to reach to the pod but when I hit internal LB ip with 8080 I am getting this error "stream timeout"

http://10.30.0.4:8080/validation/api/v1/lbhealth ----------------------------> 10.30.0.4:8080 is the frontend ip of internal LB http://10.80.9.36:8080/validation/api/v1/lbhealth -----------------------------> 10.80.9.36:8080 is the pod ip of my gke cluster

I just want reach my pods using internal Loadbalancer frontend IP

i have enabled firewall rule for internal LB subnet but not able to reach to my pods

here are some screenshots of Loadbalancer and Network endpoint group

internal LB

internal LB backend

Network endpoint group