Unable to access HAProxy Router statistics in OpenShift 3.x

Issue

HAProxy statistics page is no longer accessible after updating to OpenShift 3.6:

# oc rsh router-1-xx123 
sh-4.2$ curl -u admin:password localhost:1936
Forbidden: User "system:anonymous" cannot get routers.route.openshift.io at the cluster scope

Or this is returned:

# oc rsh router-1-xx123 
sh-4.2$ curl -u admin:password localhost:1936
404 page not found