When using name default in CRD, the controllerNamePrefix is fixed to nginx

[JoeyC-Dev]

az aks approuting enable --resource-group $resourceGroup --name $clusterName --nginx None

Change metadata.name to the name other than default will not encounter the issue.

apiVersion: approuting.kubernetes.azure.com/v1alpha1
kind: NginxIngressController
metadata:
  name: default
spec:
  ingressClassName: webapprouting.kubernetes.azure.com
  controllerNamePrefix: testprefix

[OliverMKing]

This is by design (for compatibility with older iterations of app routing). This edge case should be documented somewhere @sabbour.