This usually happens because your GitHub Actions IAM role isn’t mapped to a Kubernetes RBAC user in EKS. To fix it, confirm which IAM identity is being used with `aws sts get-caller-identity` and `kubectl whoami`, then check the `aws-auth` ConfigMap with `kubectl get configmap aws-auth -n kube-system -o yaml`. If your GitHub Actions IAM role isn’t listed there, add it. That’s the step that wires up authentication properly.