Using GCLB with istio-ingressgateway

Hello all,
Help needed. I have setup istio service mesh and have my ingressgateway built out. The issue is trying to setup a Google GCLB mapped to cloudflare is not working when attached to the istio ingressgateway NEGS. I have switched the ingressgateway to NodePort for this but still nothing seems to work. Has anyone used istio ingressgateway with Google Load balancers?