Sail, Ubuntu & spaite/ray

Having trouble getting Spatie's Ray working after fresh install via https://laravel.build. My host machine is Linux Mint / Ubuntu.

Anyone know what I'm doing wrong?

(Just sticking with the framework agnostic install for now (ultimate goal is to get this working in another project, but wanted to use Sail's web host container to eliminate that project's very custom container as a cause))

docker-compose.yml:

    laravel.test:
        build:
            context: ./vendor/laravel/sail/runtimes/8.1
            dockerfile: Dockerfile
        extra_hosts:
            - 'host.docker.internal:host-gateway'
        ports:
            - '${APP_PORT:-80}:80'
        volumes:
            - '.:/var/www/html'
        networks:
            - sail

ray.php:

return [
    'enable' => true,
    'host' => 'host.docker.internal',
    'port' => 23517,
    'remote_path' => '/var/www/html',
    'local_path' => '/home/itsme/Code/example-app',
    'always_send_raw_values' => false,
];

Host machine /etc/hosts:

127.0.0.1 host.docker.internal

/etc/hosts within laravel.test container:

172.17.0.1    host.docker.internal

Ray is listening on my machine:

$ sudo netstat -tupl | grep 23517                                                               
tcp6       0      0 [::]:23517              [::]:*                  LISTEN      342313/ray    

From host machine, can get a response from Ray:

$ curl -I http://host.docker.internal:23517/_availability_check                            
HTTP/1.1 404 Not Found
X-Powered-By: Express
Access-Control-Allow-Origin: *
Content-Security-Policy: default-src 'none'
X-Content-Type-Options: nosniff
Content-Type: text/html; charset=utf-8
Content-Length: 159

From within laravel.test container, cannot talk to Ray:

$ curl -I http://host.docker.internal:23517/_availability_check    
curl: (28) Failed to connect to host.docker.internal port 23517: Connection timed out