OpenShift Authentication Operator in Degraded state with the error: ProxyConfigControllerDegraded after configuring a custom certificate for OAuth server URL

Issue

• Authentication Operator is degraded with error message

  'ProxyConfigControllerDegraded: endpoint("https://oauth-openshift.apps.<clusterdomain>/healthz")
    found in NO_PROXY(".cluster.local,.svc ... etc)
    is unreachable with proxy(Get "https://oauth-openshift.apps.<clusterdomain>/healthz":
    context deadline exceeded) and without proxy(Get "https://oauth-openshift.apps.<clusterdomain>/healthz":
    tls: failed to verify certificate: x509: certificate signed by unknown authority)'
  

• After Customizing the internal OAuth server URL with a custom certificate following this procedure the Authentication Operator is in a degraded state.