Ingress -> Cluster IP back-end - got ERR_CONNECTION_REFUSED - kubernetes

Question

I got ingress defined as:
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: wp-ingress
namespace: wordpress
annotations:
kubernetes.io/ingress.class: nginx
nginx.ingress.kubernetes.io/ssl-redirect: "true"
nginx.ingress.kubernetes.io/proxy-body-size: 25m
spec:
rules:
- host: my.domain.com
http:
paths:
- path: /
backend:
serviceName: wordpress
servicePort: 6002
And the back-end, defined as Cluster IP running on 6002 port.
When I am trying to reach ingress by its ADDRESS in the browser I get ERR_CONNECTION_REFUSED.
I suspect it has to do with the back-end?
Q: What could be a problem? How to analyse it? to make it work.
See the picture below, it is on GCP, all ips are resolved. All seems connected to each other.
The nginx-ingress (ingress-controller, default backed) was installed as helm chart.
helm install --namespace wordpress --name wp-nginx-ingress stable/nginx-ingress --tls
UPDATE:
I do not use yet (https) for back-end, tried to remove http redirect from the ingress yml: nginx.ingress.kubernetes.io/ssl-redirect: "true" removed - did not help.
UPDATE2: wordpress yaml - got from running service at yaml tab in GCP->KE->Services
apiVersion: v1
kind: Service
metadata:
creationTimestamp: "2020-03-30T04:11:12Z"
labels:
app.kubernetes.io/instance: wordpress
app.kubernetes.io/managed-by: Tiller
app.kubernetes.io/name: wordpress
helm.sh/chart: wordpress-9.0.4
name: wordpress
namespace: wordpress
resourceVersion: "2518308"
selfLink: /api/v1/namespaces/wordpress/services/wordpress
uid: 7dac1a73-723c-11ea-af1a-42010a800084
spec:
clusterIP: xxx.xx.xxx.xx
ports:
- name: http
port: 6002
protocol: TCP
targetPort: http
- name: https
port: 443
protocol: TCP
targetPort: https
selector:
app.kubernetes.io/instance: wordpress
app.kubernetes.io/name: wordpress
sessionAffinity: None
type: ClusterIP
status:
loadBalancer: {}
UPDATE: 3
I tried:
kubectl -n wordpress exec -it wordpress-xxxx-xxxx -- /bin/bash
curl http://wordpress.wordpress.svc.cluster.local:6002 and it works - it gets me the html from the wordpress.