Istio Ingress gateway unable to connect To AKS Application Gateway

I have deployed Istio version 1.10 on AKS version 1.19. Now I wanted to set Istio Ingress gateway as an internal load balancer and configure it with Application gateway on Azure. Added the following annotation in ingress gateway deployment : service.beta.kubernetes.io/azure-load-balancer-internal: “true”. After adding the external IP to the backend pool of the application gateway on azure I am getting the following error and status is Unhealthy:

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And the istio ingress gateway logs shows:

[2021-07-06T10:52:39.345Z] "- - -" 0 NR filter_chain_not_found - "-" 0 0 0 - "-" "-" "-" "-" "-" - - <ip>:8443 <ip>:36333 - -
[2021-07-06T10:53:07.199Z] "- - -" 0 NR filter_chain_not_found - "-" 0 0 0 - "-" "-" "-" "-" "-" - - <ip>:8443 <ip>:17313 - -

Can any one help me with this? Do I have to do any other configurations?