Namespace disappears from Kiali when deleted and recreated

When I delete a namespace and then recreate it, it doesn't show up in the Namespace drop-down in Kiali.

Steps to reproduce:

1. Add namespace foo to ServiceMeshMemberRoll.spec.members.
2. Confirm that it's visible in the Namespace drop-down in Kiali.
3. Delete namespace
4. Confirm that the namespace is no longer shown in the drop-down.
5. Recreate the namespace
6. Namespace should reappear in the drop-down, but it never does.

The kiali.io/member-of label is never added to the new namespace:

$ oc get ns foo -L kiali.io/member-of
NAME   STATUS   AGE     MEMBER-OF
foo    Active   2m45s   istio-system

$ oc delete ns foo
namespace "foo" deleted

$ oc new-project fo
...

$ oc get ns foo -L kiali.io/member-of
NAME   STATUS   AGE   MEMBER-OF
foo    Active   1m5s             <----- no label

If I then add the label manually, the namespace appears in the drop-down.