Unable to get HTTPS to work using LetsEncrypt

JupyterHub Zero to JupyterHub on Kubernetes
1

Although I’m not an IT professional, I successfully deployed the most basic Z2JH on Google’s GKE. I configured it with a static external IP, and in its initial form, I can access it by pointing my browser at http://my_domain_name

The Z2JH documentation makes it sound very simple to enable https access by following the instructions found at Set Up Automatic HTTPS

But doing the above breaks everything: I can’t get in with either http or https. Error message in the browser say things like, "the site may be down or have moved’, so it doesn’t seem to be strictly a certificate problem. I’ve confirmed that the static external IP is still being used by Kubernetes,

If I revert to the non-https-enabling config.yaml file, then I regain access via http.

I’m guessing I’m not the first to have this problem, given that (so far) I’m not knowingly doing anything that deviates from the most basic setup described in the docs. I’d welcome advice on how to debug/fix this problem.

### Installation info
  - Kubernetes namespace: jupyter
  - Helm release name:    my-jupyterhub
  - Helm chart version:   3.3.7
  - JupyterHub version:   4.1.5
  - Hub pod packages:     See https://github.com/jupyterhub/zero-to-jupyterhub-k8s/blob/71ecf69f2f04ae5426ab7602c2844499b36bfc66/images/hub/requirements.txt

Here’s my config.yaml file:

proxy:
  service:
    type: LoadBalancer
    loadBalancerIP: <my static ip>
  https:
    enabled: true
    hosts:
      - <my domain name>
    letsencrypt:
      contactEmail: <my email>

I’d post more info about my setup, but I’m not sure what would be most useful, so I’ll wait for specific suggestions for what to look at.