How do I point Kubernetes Ingress to the Istio ingress gateway?

I have a currently functioning Istio application. I would now like to add HTTPS using the Google Cloud managed certs. I setup the ingress there like this...

apiVersion: networking.gke.io/v1
kind: ManagedCertificate
metadata:
  name: managed-cert
  namespace: istio-system
spec:
  domains:
    - mydomain.co
---
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: managed-cert-ingress
  namespace: istio-system
  annotations:
    kubernetes.io/ingress.global-static-ip-name: managed-cert
    networking.gke.io/managed-certificates: managed-cert
    kubernetes.io/ingress.class: "gce"
spec:
  defaultBackend:
    service:
      name: istio-ingressgateway
      port:
        number: 443
---

But when I try going to the site (https://mydomain.co) I get...

Secure Connection Failed

An error occurred during a connection to earth-615.mydomain.co. Cannot communicate securely with peer: no common encryption algorithm(s).

Error code: SSL_ERROR_NO_CYPHER_OVERLAP

The functioning virtual service/gateway looks like this...

apiVersion: networking.istio.io/v1beta1
kind: Gateway
metadata:
  name: ingress-gateway
  namespace: istio-system
  annotations:
    kubernetes.io/ingress.global-static-ip-name: earth-616
spec:
  selector:
    istio: ingressgateway
  servers:
    - port:
        number: 80
        name: http2
        protocol: HTTP2
      hosts:
        - "*"
---
apiVersion: networking.istio.io/v1beta1
kind: VirtualService
metadata:
  name: test-app
  namespace: foo
spec:
  hosts:
    - "*"
  gateways:
    - "istio-system/ingress-gateway"
  http:
    - match:
        - uri:
            exact: /
      route:
        - destination:
            host: test-app
            port:
              number: 8000