Path rewrite issue

Traefik Traefik v1
1

I am trying to reach the longhorn front-end under a different path (mydomain.com/lh) in k3s using PathPrefixStrip with traefik 1.7, but something is not working properly with my ingress config, resulting in a blank page after the basic auth pop-up.

This is the ingress config I am using:

apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: longhorn-ingress
  namespace: longhorn-system
  annotations:
    # use traefik as ingress controller
    kubernetes.io/ingress.class: traefik
    # type of authentication
    traefik.ingress.kubernetes.io/auth-type: basic
    # prevent the controller from redirecting (308) to HTTPS
    traefik.ingress.kubernetes.io/ssl-redirect: 'false'
    # name of the secret that contains the user/password definitions
    traefik.ingress.kubernetes.io/auth-secret: basic-auth 
    # trying to get the frontend service to be reachable at mydomain.com/lh
    traefik.ingress.kubernetes.io/rule-type: PathPrefixStrip
spec:
  rules:
  - http:
      paths:
      - path: /lh
        backend:
          serviceName: longhorn-frontend
          servicePort: 80

When I expose the service under / and remove the PathPrefixStrip annotation, I can reach the front-end just fine at mydomain.com

What am I missing in my rewrite logic?