Why are healthcheck results different?

Question

Docker

Set up the simplest healthcheck in docker containers:
curl -s http://localhost:6000
Containers have identical web services. When executed, the docker psstatus of all containers is healthy , however, when executed, the docker inspect containernamestatus of some containers is unhealthy , which does not match the output of "docker ps". What could be wrong?
Ubuntu 14.04.5 LTS, docker 18.06.1-ce