Kong Ingress Controller: having problem with ingress at root path

[mshamim69]

1. I have setup kubernetes-ingress-controller:2.9.3 with postgres. Used kong-proxy service as type NodePort
2. Used JWT plugin (jwt-test)
   apiVersion: configuration.konghq.com/v1
   kind: KongPlugin
   metadata:
   name: jwt-test
   config:
   secret_is_base64: false
   run_on_preflight: true
   plugin: jwt
3. Created Consumer and got JWT credentials.
4. Created Services and Routes using kong admin api (port 8001) in Kubernetes JOB. For example:
   curl -i -X POST http://kong-admin:8001/services --data name=test_service --data url="??????";
   curl -i -X POST http://kong-admin:8001/services/test_service/routes --data ??????
5. Then I created Ingress as follows:

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: kong-ingress-jwt
annotations:
konghq.com/strip-path: 'true'
konghq.com/plugins: jwt-test
spec:
ingressClassName: kong
tls:
- hosts:
- kong.example.com
secretName: test-cert
rules:
- host: kong.example.com
http:
paths:
- path: /ep-jwt
pathType: ImplementationSpecific
backend:
service:
name: kong-proxy
port:
number: 80

kubectl get node -o wide provides INTERNAL-IP
Added in /etc/hosts: kong.example.com

Then the api call to route i.e http://kong.example.com:NODEPORT/ep-jwt/ROUTE works fine with JWT Bearer token.

But if I change the ingress (path /ep-jwt to /):
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
name: edge-kong-ingress-jwt
annotations:
konghq.com/strip-path: 'true'
konghq.com/plugins: jwt-test
spec:
ingressClassName: kong
tls:
- hosts:
- kong.example.com
secretName: test-cert
rules:
- host: kong.example.com
http:
paths:
- path: /
pathType: ImplementationSpecific
backend:
service:
name: kong-proxy
port:
number: 80
Then the API call to route i.e http://kong.example.com:NODEPORT/ROUTE returns Bad Request

I tried both strip-path true and false.
Any guideline what I am missing?