ApplicationLoadBalancedFargateService with load balancer, target groups, targets on non-standard port

I have an ECS service that exposes port 8080. I want to have the load balancer, target groups and target use that port as opposed to port 80. Here is a snippet of my code:

    const servicePort = 8888;
    const metricsPort = 8888;

    const taskDefinition = new ecs.FargateTaskDefinition(this, 'TaskDef');
    const repository = ecr.Repository.fromRepositoryName(this, 'cloud-config-server', 'cloud-config-server');

    taskDefinition.addContainer('Config', {
      image: ecs.ContainerImage.fromEcrRepository(repository),
      portMappings: [{containerPort : servicePort, hostPort: servicePort}],
    });
    
    const albFargateService = new ecsPatterns.ApplicationLoadBalancedFargateService(this, 'AlbConfigService', {
      cluster,
      publicLoadBalancer : false,
      taskDefinition: taskDefinition,
      desiredCount: 1,
    });

    const applicationTargetGroup = new elbv2.ApplicationTargetGroup(this, 'AlbConfigServiceTargetGroup', {
      targetType: elbv2.TargetType.IP,
      protocol: elbv2.ApplicationProtocol.HTTP,
      port: servicePort,
      vpc,
      healthCheck: {path: "/CloudConfigServer/actuator/env/profile", port: String(servicePort)}
    });

    const addApplicationTargetGroupsProps: elbv2.AddApplicationTargetGroupsProps = {
      targetGroups: [applicationTargetGroup],
    };

    albFargateService.loadBalancer.addListener('alb-listener', {
      protocol: elbv2.ApplicationProtocol.HTTP, port: servicePort, defaultTargetGroups: [applicationTargetGroup]}
    );
  }    
}

This does not work. The health check is taking place on port 80 with the default URL of "/" which fails, and the tasks are constantly recycled. A target group on port 8080, with the appropriate health check, is added, but it has no targets.

What is the recommended way to achieve load balancing on a port other than 80?

thanks