Not sure if anyone else has experienced this same problem, but I was able to fix it! Option #1 seems closest to reality. From my understanding, Kubernetes-owned load balancers should be configured completely using Kubernetes annotations, not through the UI. These resources helped me determine what was going on:

• How to configure a DigitalOcean Load Balancer with DNS routing from Kubernetes

• List of DigitalOcean Load Balancer Annotations

• Push-to-Deploy on DigitalOcean Kubernetes Using GitHub Actions

• Helpful repo from the link above that has a good starter deployment.yml file

And in case anyone else is also trying to setup a load balancer with SSL redirect and a DigitalOcean-managed SSL certificate, here’s my final service definition:

apiVersion: v1
kind: Service
metadata:
  name: frontend-service
  annotations:
    service.beta.kubernetes.io/do-loadbalancer-certificate-id: "your-certificate-id-here"
    service.beta.kubernetes.io/do-loadbalancer-hostname: "crusty.cards"
    service.beta.kubernetes.io/do-loadbalancer-protocol: "http"
    service.beta.kubernetes.io/do-loadbalancer-redirect-http-to-https: "true"
    service.beta.kubernetes.io/do-loadbalancer-tls-ports: "443"
spec:
  type: LoadBalancer
  ports:
    - name: http
      port: 80
      targetPort: 80
    - name: https
      port: 443
      targetPort: 80
  selector:
    app: frontend

If anyone from the DigitalOcean team is reading this… I think it would make a lot of sense to disallow modification of load balancer settings through the UI for Kubernetes-managed load balancers, and instead state that all settings must be changed through the use of annotations, and provide links to some of the resources listed above. That would have saved me hours of work and frustration.