Max message rate not working.

I am trying to apply max message rate in my vernemq docker container. But it is not working and my clients can send bulks of messages in a second
This is my docker compose file. here i am setting max rate.

vernemq:
    image: vernemq/vernemq
    container_name: vernemq
    restart: always
    environment:
      DOCKER_VERNEMQ_ALLOW_ANONYMOUS: 'off'
      DOCKER_VERNEMQ_PLUGINS.vmq_diversity: 'on'
      DOCKER_VERNEMQ_PLUGINS.vmq_passwd: 'off'
      DOCKER_VERNEMQ_PLUGINS.vmq_acl: 'off'
      DOCKER_VERNEMQ_VMQ_DIVERSITY.auth_mysql.enabled: 'on'
      DOCKER_VERNEMQ_VMQ_DIVERSITY.mysql.host: mysql_nest
      DOCKER_VERNEMQ_VMQ_DIVERSITY.mysql.port: $DATABASE_PORT
      DOCKER_VERNEMQ_VMQ_DIVERSITY.mysql.user: $DATABASE_USER
      DOCKER_VERNEMQ_VMQ_DIVERSITY.mysql.password: $DATABASE_PASSWORD
      DOCKER_VERNEMQ_VMQ_DIVERSITY.mysql.database: $DATABASE_DB
      DOCKER_VERNEMQ_VMQ_DIVERSITY.mysql.password_hash_method: 'md5'
      DOCKER_VERNEMQ_ACCEPT_EULA: 'yes' 
      DOCKER_VERNEMQ_MAX_MESSAGE_RATE: '2'
    ports:
      - $MQTT_MQTT_PORT:1883
      - $MQTT_WS_PORT:8080
      - $MQTT_ADMIN_PORT:8888
    networks:
      - vernemq-network
    depends_on:
      - mysql_nest

I can see max_message_rate=2 in vernemq.conf file. But still it is not working

For reference, see [Bug]: Question on max_message_rate · Issue #2177 · vernemq/vernemq · GitHub.
Thank you.