Helm - Kubernetes cluster unreachable: the server has asked for the client to provide credentials

I'm trying to deploy an EKS self managed with Terraform. While I can deploy the cluster with addons, vpc, subnet and all other resources, it always fails at helm:

Error: Kubernetes cluster unreachable: the server has asked for the client to provide credentials
with module.eks-ssp-kubernetes-addons.module.ingress_nginx[0].helm_release.nginx[0]
on .terraform/modules/eks-ssp-kubernetes-addons/modules/kubernetes-addons/ingress-nginx/main.tf line 19, in resource "helm_release" "nginx":
resource "helm_release" "nginx" {

This error repeats for metrics_server, lb_ingress, argocd, but cluster-autoscaler throws:

Warning: Helm release "cluster-autoscaler" was created but has a failed status.
with module.eks-ssp-kubernetes-addons.module.cluster_autoscaler[0].helm_release.cluster_autoscaler[0]
on .terraform/modules/eks-ssp-kubernetes-addons/modules/kubernetes-addons/cluster-autoscaler/main.tf line 1, in resource "helm_release" "cluster_autoscaler":
resource "helm_release" "cluster_autoscaler" {

My main.tf looks like this:

terraform {

  backend "remote" {}

  required_providers {
    aws = {
      source  = "hashicorp/aws"
      version = ">= 3.66.0"
    }
    kubernetes = {
      source  = "hashicorp/kubernetes"
      version = ">= 2.7.1"
    }
    helm = {
      source  = "hashicorp/helm"
      version = ">= 2.4.1"
    }
  }
}

data "aws_eks_cluster" "cluster" {
  name = module.eks-ssp.eks_cluster_id
}

data "aws_eks_cluster_auth" "cluster" {
  name = module.eks-ssp.eks_cluster_id
}

provider "aws" {
  access_key = "xxx"
  secret_key = "xxx"
  region     = "xxx"
  assume_role {
    role_arn = "xxx"
  }
}

provider "kubernetes" {
  host                   = data.aws_eks_cluster.cluster.endpoint
  cluster_ca_certificate = base64decode(data.aws_eks_cluster.cluster.certificate_authority.0.data)
  token                  = data.aws_eks_cluster_auth.cluster.token
}

provider "helm" {
  kubernetes {
    host                   = data.aws_eks_cluster.cluster.endpoint
    token                  = data.aws_eks_cluster_auth.cluster.token
    cluster_ca_certificate = base64decode(data.aws_eks_cluster.cluster.certificate_authority.0.data)
  }
}

My eks.tf looks like this:

module "eks-ssp" {
    source = "github.com/aws-samples/aws-eks-accelerator-for-terraform"

    # EKS CLUSTER
    tenant            = "DevOpsLabs2b"
    environment       = "dev-test"
    zone              = ""
    terraform_version = "Terraform v1.1.4"

    # EKS Cluster VPC and Subnet mandatory config
    vpc_id             = "xxx"
    private_subnet_ids = ["xxx","xxx", "xxx", "xxx"]

    # EKS CONTROL PLANE VARIABLES
    create_eks         = true
    kubernetes_version = "1.19"

  # EKS SELF MANAGED NODE GROUPS
    self_managed_node_groups = {
    self_mg = {
      node_group_name        = "DevOpsLabs2b"
      subnet_ids             = ["xxx","xxx", "xxx", "xxx"]
      create_launch_template = true
      launch_template_os     = "bottlerocket"       # amazonlinux2eks  or bottlerocket or windows
      custom_ami_id          = "xxx"
      public_ip              = true                   # Enable only for public subnets
      pre_userdata           = <<-EOT
            yum install -y amazon-ssm-agent \
            systemctl enable amazon-ssm-agent && systemctl start amazon-ssm-agent \
        EOT

      disk_size     = 10
      instance_type = "t2.small"
      desired_size  = 2
      max_size      = 10
      min_size      = 0
      capacity_type = "" # Optional Use this only for SPOT capacity as  capacity_type = "spot"

      k8s_labels = {
        Environment = "dev-test"
        Zone        = ""
        WorkerType  = "SELF_MANAGED_ON_DEMAND"
      }

      additional_tags = {
        ExtraTag    = "t2x-on-demand"
        Name        = "t2x-on-demand"
        subnet_type = "public"
      }
      create_worker_security_group = false # Creates a dedicated sec group for this Node Group
    },
  }
}

    enable_amazon_eks_vpc_cni             = true
        amazon_eks_vpc_cni_config = {
        addon_name               = "vpc-cni"
        addon_version            = "v1.7.5-eksbuild.2"
        service_account          = "aws-node"
        resolve_conflicts        = "OVERWRITE"
        namespace                = "kube-system"
        additional_iam_policies  = []
        service_account_role_arn = ""
        tags                     = {}
    }
    enable_amazon_eks_kube_proxy          = true
        amazon_eks_kube_proxy_config = {
        addon_name               = "kube-proxy"
        addon_version            = "v1.19.8-eksbuild.1"
        service_account          = "kube-proxy"
        resolve_conflicts        = "OVERWRITE"
        namespace                = "kube-system"
        additional_iam_policies  = []
        service_account_role_arn = ""
        tags                     = {}
    }

    #K8s Add-ons
    enable_aws_load_balancer_controller   = true
    enable_metrics_server                 = true
    enable_cluster_autoscaler             = true
    enable_aws_for_fluentbit              = true
    enable_argocd                         = true
    enable_ingress_nginx                  = true

    depends_on = [module.eks-ssp.self_managed_node_groups]
}

OP has confirmed in the comment that the problem was resolved:

Of course. I think I found the issue. Doing "kubectl get svc" throws: "An error occurred (AccessDenied) when calling the AssumeRole operation: User: arn:aws:iam::xxx:user/terraform_deploy is not authorized to perform: sts:AssumeRole on resource: arn:aws:iam::xxx:user/terraform_deploy"

Solved it by using my actual role, that's crazy. No idea why it was calling itself.

For similar problem look also this issue.