I'm on GKE and nginx version controller-v1.0.0.

I'm trying extend timeout to 300s (or more) but I'm able to extend only to 120s with success. With any greater value, the session hangs indefinitely. My config:

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: name-of-ingerss
  namespace: somens
  annotations:
    kubernetes.io/ingress.class: "nginx"
    cert-manager.io/cluster-issuer: "letsencrypt-prod-cluster"
    nginx.ingress.kubernetes.io/proxy-read-timeout: "120"
    nginx.ingress.kubernetes.io/proxy-send-timeout: "120"