I meet a problem, described at https://github.com/containous/traefik/issues/5387.
And I don't think it is a RBAC config mistake, because I have never changed config related and everything works all the time before this backend upgrade. Even though I re-apply traefik and RBAC config to solve problem, but age of resources include clusterrole, clusterrolebinding, serviceaccount, secret of token, deploy and pod of traefik, ingress of traefik are not updated.