Kibana@Docker new instances occure in stack monitoring when I reboot the Kibana node

Hi There,
I'm running on elk 7.9.2 with two kibana's nodes.
I'm noticing some interesting behaviour in the stack monitoring
kibana_mirror

.
When I reboot one of two kibana's node then I've lost my monitoring graphs and I start from the beginning (see snapshots)

Is this because I haven't linked some persisten volume ?
See my kibana.yml and docker-compose.yml (they are same for both nodes)
kibana.yml

server.port: 5601
server.host: "0.0.0.0"
server.name: "kib01d"
elasticsearch.hosts: ["https://xxx:9200","https://xxx:9200","https://xxx:9200"]
server.ssl.enabled: true
elasticsearch.username: "kibana_system"
elasticsearch.password: "xxx"

server.ssl.certificate: /usr/share/kibana/config/certs/xxx.crt
server.ssl.key: /usr/share/kibana/config/certs/xxx.key

elasticsearch.ssl.certificateAuthorities: [ "/usr/share/kibana/config/certs/ca/ca.crt" ]

elasticsearch.ssl.verificationMode: certificate

pid.file: /usr/share/kibana/kibana.pid
logging.verbose: true
logging.dest: /usr/share/kibana/logs/kibana.log
xpack.security.encryptionKey: "xxx"
xpack.encryptedSavedObjects.encryptionKey: "xxx"
#xpack.monitoring.collection.enabled: true
xpack.ml.enabled: true
telemetry.enabled: false

docker-compose.yml:

version: '3'
services:
  kib01d:
    image: /elk/kibana/kibana:7.9.2
    container_name: kib01d
    environment:
      - bootstrap.memory_lock=true
      - publish-all
      - ES_JAVA_OPTS="-Xms16G -Xmx16G"
    ulimits:
      memlock:
        soft: -1
        hard: -1
    volumes:
      - /srv/Docker/config:/usr/share/kibana/config
      - /srv/Docker/logs:/usr/share/kibana/logs
    dns:
    
    dns_search: xxx.xx
    ports:
      - 5601:5601
    network_mode: "host"
  metricbeats:
    image: harbor.upc.pl/elk/beats/metricbeat:7.9.2
    container_name: metricbeat05
    environment:
       - publish-all
    user: root
    depends_on:
      - kib01d
    command: metricbeat -e -E name=MB_Kibana_1
    volumes:
      - "/srv/Docker/metricbeat/metricbeat.yml:/usr/share/metricbeat/metricbeat.yml:ro"
      - "/var/run/docker.sock:/var/run/docker.sock:ro"
      - "/srv/Docker/metricbeat/modules.d:/usr/share/metricbeat/modules.d"
      - "/sys/fs/cgroup:/hostfs/sys/fs/cgroup:ro"
      - "/proc:/hostfs/proc:ro"
      - "/:/hostfs:ro"
      - "/srv/Docker/config:/usr/share/kibana/config"

Any ideas ?

Monitoring data are written to the Elasticsearch. I don't see it in the provided docker-compose.yml file.
How do you configure it? Does the elasticsearch docker configuration define volumes to persist data across restarts?

If you ask about how does metricbeat send the monitoring data to ELK, here you have a part of the metricbeat.yml:

#========================== Elasticsearch output ===============================
output.elasticsearch:
  hosts: ["https://x:9200", "https://xxl:9200", "https://xxx:9200"]
  username: "elastic"
  password: "xxx"
  ssl.verification_mode: "full"
  ssl.certificate_authorities: /usr/share/kibana/config/certs/ca/ca.crt

Allright Folks,

I know what happened there. Two things acctually:

  1. I used docker-compose down & up (it's removing the container and create the new UUID)
  2. I didn't create any persistent volume for keeping /usr/share/kibana/data

When 2) was done then 1) disappeared even when I use command docker-compose down/up