Setting CNB_PORT doesn't work at all

i’m trying to set up a simple static site to deploy with autodevops. I am using KAS to deploy to my kubernetes cluster. The problem I am struggling with is changing the port the default helm chart is expecting my application to run on.

I am using paketobuildpacks/builder:base as my builder to put my application into an nginx container via the BP_WEB_SERVER variable.

here is my .gitlab-ci.yml file

variables:
  POSTGRES_ENABLED: "false"
  AUTO_DEVOPS_BUILD_IMAGE_CNB_PORT: "8080"
  BP_WEB_SERVER: nginx
  AUTO_DEVOPS_BUILD_IMAGE_CNB_ENABLED: "true"
  AUTO_DEVOPS_BUILD_IMAGE_CNB_BUILDER: paketobuildpacks/builder:base
  AUTO_DEVOPS_BUILD_IMAGE_FORWARDED_CI_VARIABLES: "BP_WEB_SERVER"
  SAST_DISABLED: "true"
  LICENSE_MANAGEMENT_DISABLED: "true"
  DEPENDENCY_SCANNING_DISABLED: "true"
  DAST_DISABLED: "true"
  CONTAINER_SCANNING_DISABLED: "true"
  CODE_QUALITY_DISABLED: "true"
  PERFORMANCE_DISABLED: "true"
  TEST_DISABLED: "true"
  SECRET_DETECTION_DISABLED: "true"

include:
    - template: Auto-DevOps.gitlab-ci.yml

When my application deploys, the target port is always 5000 even though I have specified AUTO_DEVOPS_BUILD_IMAGE_CNB_PORT variable in my job.

Is my understanding of AUTO_DEVOPS_BUILD_IMAGE_CNB_PORT or is this completely brokern?

I am running on-prem gitlab 15.4.2

$ kubectl describe svc -n website
Name:              staging-auto-deploy
Namespace:         website
Labels:            app=staging
                   app.kubernetes.io/instance=staging
                   app.kubernetes.io/managed-by=Helm
                   app.kubernetes.io/name=staging
                   chart=auto-deploy-app-2.35.0
                   helm.sh/chart=auto-deploy-app-2.35.0
                   heritage=Helm
                   release=staging
                   track=stable
Annotations:       meta.helm.sh/release-name: staging
                   meta.helm.sh/release-namespace: website
Selector:          app=staging,tier=web,track=stable
Type:              ClusterIP
IP Family Policy:  SingleStack
IP Families:       IPv4
IP:                10.43.190.219
IPs:               10.43.190.219
Port:              web  5000/TCP
TargetPort:        5000/TCP
Endpoints:
Session Affinity:  None
Events:            <none>

Thanks