New ECS service (on EC2) behind existing load balancer, blank listener protocol:port

Hi all,

I have an ECS Optimized EC2 instance into which we have been launching our containers along with an application load balancer that all of the applications sit behind. I just attempted to launch a new service, however, when reviewing the service configuration, under the main Health and metrics tab, it does not show any information under the Listener protocol:port section. See the screenshot below.

Everything else looks fine, the security group attached to the EC2 instance is allowing All TCP ports from the load balancer so the ephemeral ports are all covered. This same configuration is working for other services. It's not clear what is causing the issue for this particular service.