Juju trust not working for K8s charm

When deployed with --trust, a charm isn't getting elevated permissions with Juju 2.9.22.

$ juju config istio-pilot | grep -A 5 trust:
  trust:
    default: false
    description: Does this application have access to trusted credentials
    source: user
    type: bool
    value: true

$ microk8s kubectl get roles/istio-pilot-operator -nkubeflow -oyaml
...
rules:
- apiGroups:
  - ""
  resources:
  - pods
  - services
  verbs:
  - get
  - list
  - patch
- apiGroups:
  - ""
  resources:
  - pods/exec
  verbs:
  - create

Running `juju config istio-pilot trust=false; juju trust --scope=cluster istio-pilot` doesn't seem to have any effect.