Canary Upgrade fails with Gateway in different namespace

[aadhik]

I have a central gateway in istio-system namespace , virtual services are created in different namespaces .
When doing canary upgrade , get below error and its fails
"Referenced selector not found: "istio=istio-ingressgateway"
The configuration is correct , traffic is being correctly routed to pods . The ingress gateway pod has the correct label.

---

The upgrade is successful of i move gw to individual user namespace and create multiple gw with host defined .
My use case is to have a common gateway with "*" and route traffic based on hosts setting on VS