Mattermost Docker "/config/config.json" Permission denied

I am experimenting with mattermost docker image. I am getting Permission denied from the mattermost official docker image itself.

OS :Centos 8 Stream. User : root - running all docker-compose commands using root.

Any other docker images(eg Wordpress) works just fine.

Any clue ?

version: "3.7"
services:
  db:
    container_name: mattermost-db
    image: mysql:8.0.20
    environment:
      MYSQL_ROOT_PASSWORD: msqlroot123#
      MYSQL_DATABASE: mattermost
      MYSQL_USER: msqluser 
      MYSQL_PASSWORD: msqluser123#
    command: mysqld --default-authentication-plugin=mysql_native_password
    volumes: 
      - ./volumes/db/mysql:/var/lib/mysql
    ports:
      - "3306:3306"
    networks:
      - my-network
  app:
    #image: mattermost/mattermost-team-edition:release-5.33
    image: mattermost/mattermost-prod-app
    container_name: mattermost-docker_app_1 
    restart: unless-stopped
    volumes:
      - ./volumes/app/mattermost/config:/mattermost/config:rw
      - ./volumes/app/mattermost/data:/mattermost/data:rw
      - ./volumes/app/mattermost/logs:/mattermost/logs:rw
      - ./volumes/app/mattermost/plugins:/mattermost/plugins:rw
      - ./volumes/app/mattermost/client-plugins:/mattermost/client/plugins:rw
      - /etc/localtime:/etc/localtime:ro
    ports: 
      - "8000:8000"
    environment:
      - MM_USERNAME=msqluser
      - DB_PORT_NUMBER=3306
      - MM_DBNAME=mattermost
      - DB_HOST=mattermost-db
      - VIRTUAL_HOST=mattermost.abcinc.com
      - VIRTUAL_PORT=8000
      - LETSENCRYPT_HOST=mattermost.abcinc.com
      - MM_USERNAME=mmuser
      - MM_PASSWORD=mmuser_password
      - edition=team
    networks:
      - my-network
networks:
  my-network:
    external:
      name: my-network

The important step is described here: https://github.com/mattermost/mattermost-docker#startingstopping-docker

chown -R 2000:2000 ./volumes/app/mattermost/

You might need to use sudo