Session affinity cookie not working anymore (Kubernetes with Nginx ingress)

An upgrade of our Azure AKS - Kubernetes environment to Kubernetes version 1.19.3 forced me to also upgrade my Nginx helm.sh/chart to nginx-ingress-0.7.1. As a result I was forced to change the API version definition to networking.k8s.io/v1 since my DevOps pipeline failed accordingly (a warning for old API resulting in an error). However, now I have the problem that my session affinity annotation is ignored and no session cookies are set in the response.

I am desperately changing names, trying different unrelated blog posts to somehow fix the issue.

Any help would be really appreciated.

My current nginx yaml (I have removed status/managed fields tags to enhance readability):

kind: Deployment
apiVersion: apps/v1
metadata:
  name: nginx-ingress-infra-nginx-ingress
  namespace: ingress-infra 
  labels:
    app.kubernetes.io/instance: nginx-ingress-infra
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/name: nginx-ingress-infra-nginx-ingress
    helm.sh/chart: nginx-ingress-0.7.1
  annotations:
    deployment.kubernetes.io/revision: '1'
    meta.helm.sh/release-name: nginx-ingress-infra
    meta.helm.sh/release-namespace: ingress-infra
spec:
  replicas: 2
  selector:
    matchLabels:
      app: nginx-ingress-infra-nginx-ingress
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: nginx-ingress-infra-nginx-ingress
      annotations:
        prometheus.io/port: '9113'
        prometheus.io/scrape: 'true'
    spec:
      containers:
        - name: nginx-ingress-infra-nginx-ingress
          image: 'nginx/nginx-ingress:1.9.1'
          args:
            - '-nginx-plus=false'
            - '-nginx-reload-timeout=0'
            - '-enable-app-protect=false'
            - >-
              -nginx-configmaps=$(POD_NAMESPACE)/nginx-ingress-infra-nginx-ingress
            - >-
              -default-server-tls-secret=$(POD_NAMESPACE)/nginx-ingress-infra-nginx-ingress-default-server-secret
            - '-ingress-class=infra'
            - '-health-status=false'
            - '-health-status-uri=/nginx-health'
            - '-nginx-debug=false'
            - '-v=1'
            - '-nginx-status=true'
            - '-nginx-status-port=8080'
            - '-nginx-status-allow-cidrs=127.0.0.1'
            - '-report-ingress-status'
            - '-external-service=nginx-ingress-infra-nginx-ingress'
            - '-enable-leader-election=true'
            - >-
              -leader-election-lock-name=nginx-ingress-infra-nginx-ingress-leader-election
            - '-enable-prometheus-metrics=true'
            - '-prometheus-metrics-listen-port=9113'
            - '-enable-custom-resources=true'
            - '-enable-tls-passthrough=false'
            - '-enable-snippets=false'
            - '-ready-status=true'
            - '-ready-status-port=8081'
            - '-enable-latency-metrics=false'

My ingress configuration of the service name "account":

kind: Ingress
apiVersion: networking.k8s.io/v1beta1
metadata:
  name: account
  namespace: infra
  resourceVersion: '194790'
  labels:
    app.kubernetes.io/managed-by: Helm
  annotations:
    kubernetes.io/ingress.class: infra
    meta.helm.sh/release-name: infra
    meta.helm.sh/release-namespace: infra
    nginx.ingress.kubernetes.io/affinity: cookie
    nginx.ingress.kubernetes.io/proxy-buffer-size: 128k
    nginx.ingress.kubernetes.io/proxy-buffering: 'on'
    nginx.ingress.kubernetes.io/proxy-buffers-number: '4'
spec:
  tls:
    - hosts:
        - account.infra.mydomain.com
      secretName: my-default-cert **this is a self-signed certificate with cn=account.infra.mydomain.com
  rules:
    - host: account.infra.mydomain.com
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              serviceName: account
              servicePort: 80
status:
  loadBalancer:
    ingress:
      - ip: 123.123.123.123 **redacted**

My account service yaml

kind: Service
apiVersion: v1
metadata:
  name: account
  namespace: infra
  labels:
    app.kubernetes.io/instance: infra
    app.kubernetes.io/managed-by: Helm
    app.kubernetes.io/name: account
    app.kubernetes.io/version: latest
    helm.sh/chart: account-0.1.0
  annotations:
    meta.helm.sh/release-name: infra
    meta.helm.sh/release-namespace: infra
spec:
  ports:
    - name: http
      protocol: TCP
      port: 80
      targetPort: 80
  selector:
    app.kubernetes.io/instance: infra
    app.kubernetes.io/name: account
  clusterIP: 10.0.242.212
  type: ClusterIP
  sessionAffinity: ClientIP **just tried to add this setting to the service, but does not work either**
  sessionAffinityConfig:
    clientIP:
      timeoutSeconds: 10800
status:
  loadBalancer: {}

Ok, the issue was not related to any configuration shown above. The debug logs of the nginx pods were full of error messages in regards to the kube-control namespaces. I was removing the Nginx helm chart completely and used the repositories suggested by Microsoft:

https://learn.microsoft.com/en-us/azure/aks/ingress-own-tls

# Create a namespace for your ingress resources
kubectl create namespace ingress-basic

# Add the ingress-nginx repository
helm repo add ingress-nginx https://kubernetes.github.io/ingress-nginx

# Use Helm to deploy an NGINX ingress controller
helm install nginx-ingress ingress-nginx/ingress-nginx \
    --namespace ingress-basic \
    --set controller.replicaCount=2 \
    --set controller.nodeSelector."beta\.kubernetes\.io/os"=linux \
    --set defaultBackend.nodeSelector."beta\.kubernetes\.io/os"=linux