I have two Istio RouteRules for httpDelay:

apiVersion: config.istio.io/v1alpha2
kind: RouteRule
metadata:
  name: foo-delay
spec:
  destination:
    name: foo-server
  precedence: 5
  route:
  - labels:
      serving: "true"
  httpFault:
    delay:
      fixedDelay: 7.000s
      percent: 100

And for httpReqTimeout:

apiVersion: config.istio.io/v1alpha2
kind: RouteRule
metadata:
  name: foo-timeout-default
spec:
  destination:
    name: foo-server
  route:
  - labels:
      serving: "true"
  httpReqTimeout:
    simpleTimeout:
      timeout: 5s
  precedence: 3

However, I'm not able to make both of these RouteRules to work together. For this configuration, I have a delay to foo-server but request timeout doesn't work so I receive the data from the foo-server. I have tried to change the httpDelay rule precedence: 2. In this case don't get any delay at all, and I presume that the httpReqTimeout works fine. In both cases I can see that both rules are created:

>istioctl get routerules
NAME                KIND                    NAMESPACE
foo-delay           RouteRule.v1alpha2.config.istio.io  default
foo-timeout-default RouteRule.v1alpha2.config.istio.io  default

Why doesn't these two RouteRules work together?