For docker-compose using build with buildkit/buildx enabled, causing buildx not finding referenced images that are known by docker-host or that are provided during build.
You may require either a local or remote docker-registry. I'm not shure if buildx is able to push/pull from docker-host running buildx-container.
docker-compose build --push --pull
You can check if your docker-host has the service-a image available:
docker image ls | grep 'registry.php-stack.docker/service'
registry.php-stack.docker/service-a local c0881693c02c xx hours ago 7.34MB
To test locally you may roll-out docker-registry:v2 service. An example is provided here by docker-compose.local-registry.yml. You either must configure docker.json and buildkit.toml to allow insecure/http registry or you must rollout local mkcert to enshure ssl-trust.