haproxy permanently down (health check)

We are conducting a service test using Docker Swarm and Haproxy.

Health Check works when the service is alive, but when the web service is arbitrarily killed in the docker and the backend is down, the health check is never done in Happy again.

I want to do Health Check when the web service comes back to life after it dies.

My config file

global
    daemon

defaults
    log       global
    mode      http
    option    http-server-close
    timeout   http-request  10s
    timeout   client        20s
    timeout   connect       4s
    timeout   server        30s
    timeout   http-keep-alive   10s

frontend www
    bind *:80

    default_backend web-svr

backend web-svr

    option  httpchk HEAD /ping 

    server  server1   backend_server:8000  check fall 3 rise 2

server up status

server up status

server down status

server down status