Why can't I upgrade to version 1.12 of the managed Istio add-on?

Virtual Private Cloud Classic infrastructure

When you upgrade your managed Istio components from version 1.11 to version 1.12, the upgrade does not complete.

When you check the status of the Istio add-on, the HEALTH STATUS remains set to (1.11 --> 1.12).

Name    Version   Health State   Health Status   
istio   1.12      updating       (1.11 --> 1.12)   

Additionally, when you check the logs for the addon-istio-operator pod by running kubectl logs -n ibm-operators -l name=managed-istio-operator, you see the following error messages.

Error [IST0139] (MutatingWebhookConfiguration istio-sidecar-injector) Webhook overlaps with others: [istio-sidecar-injector/namespace.sidecar-injector.istio.io]. This may cause injection to occur twice.
Error [IST0139] (MutatingWebhookConfiguration istio-sidecar-injector) Webhook overlaps with others: [istio-sidecar-injector/sidecar-injector.istio.io]. This may cause injection to occur twice.

If the Istio add-on instance you are upgrading was provisioned at version 1.10 or earlier, there are webhook issues that must be resolved before you can upgrade to version 1.12.

To resolve the webhook errors and continue the version upgrade, follow the instructions in step 4 of Updating the minor version of the Istio add-on.

Wait for the upgrade to proceed. Then, check the Istio health status to verify that the add-on is functioning normally.

Name    Version   Health State   Health Status   
istio   1.12      normal         Addon Ready