Cannot list ECS Clusters in Jenkins configure cloud screen

I used this CloudFormation template to create my ECS Cluster https://tomgregory-cloudformation-examples.s3-eu-west-1.amazonaws.com/jenkins-for-ecs.yml

I am using Amazon Elastic Container Service (ECS) / Fargate Jenkins plugin.

I am trying to configure Configure Clouds but when I input the region eu-central-1 where I created my cluster it spins and spins and cannot list my cluster (it times out with error 504 in the browser console). I am 100% sure my cluster is located in eu-central-1 but when I select this region it doesn't find my cluster. What am I missing?

UPDATE I looked at CloudWatch logs and I found that it's permissions related

User: arn:aws:sts::{...}:assumed-role/jenkins-role/5d8e46aed4f642809856ffa57732588a is not authorized to perform: ecs:ListClusters on resource: * because no identity-based policy allows the ecs:ListClusters action (Service: AmazonECS; Status Code: 400; Error Code: AccessDeniedException)

I added a policy to the role with this statement

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "VisualEditor0",
            "Effect": "Allow",
            "Action": "ecs:ListClusters",
            "Resource": "*"
        }
    ]
}

I've confirmed in Policy Simulator that the role does have permissions to list ECS clusters but it still doesn't work.

This is the response from AWS IAM API

{
    "RoleName": "jenkins-role",
    "PolicyName": "JenkinsECSListClusters",
    "PolicyDocument": {
        "Version": "2012-10-17",
        "Statement": [
            {
                "Sid": "VisualEditor0",
                "Effect": "Allow",
                "Action": "ecs:ListClusters",
                "Resource": "*"
            }
        ]
    }
}