I have a cluster with 2 ingress classes - traefik and new-ingress both based on traefik.io/ingress-controller
My traefik ingress controller is configured to use new-ingress. This ingress controller routes traffic to the ingress resources with ingressClassName = new-ingress as well as ingress resources with ingressClassName = traefik. Ideally the ingress controller should route traffic only to the ingress resources with ingressClassName = new-ingress. If I delete the ingressClass = traffic, then the ingress controller doesn't route to the ingress resources with ingressClassName = traefik any more.
So there is a bug where ingressClassName = traefik is considered by the ingress controller by default even though there are multiple ingress classes