Unable to perform database dump

[guereeno]

Hi,
I need to dump the database and I'm tryng with the following command:

# docker exec -it mariadb mysqldump -u root -p'redactedpassword' glpidb > glpi_backup.sql

and I get an invali credential error inside the generated file:

mysqldump: Got error: 1045: "Access denied for user 'root'@'localhost' (using password: YES)" when trying to connect

Of course the credentials have been changed from the defaults during first deploy.
Here is my docker-compose.yml file:

 services:
    mariadb:
         image: mariadb:10.7
         container_name: mariadb
         hostname: mariadb
         volumes:
             - ./var/lib/mysql:/var/lib/mysql
             - /etc/timezone:/etc/timezone:ro
             - /etc/localtime:/etc/localtime:ro
         environment:
             - MARIADB_ROOT_PASSWORD='redacted'
             - MARIADB_DATABASE=glpidb
             - MARIADB_USER=glpi_user
             - MARIADB_PASSWORD='redacted'
             - MARIADB_AUTO_UPGRADE='1'
             - TIMEZONE=Europe/Rome
         restart: always
        
    glpi:
       image: diouxx/glpi:latest
       container_name : glpi
       hostname: glpi
       ports:
           - "80:80"
       volumes:
           - /etc/timezone:/etc/timezone:ro
           - /etc/localtime:/etc/localtime:ro
           - /var/www/html/glpi/:/var/www/html/glpi
       environment:
           - TIMEZONE=Europe/Rome
       restart: always

 networks:
   default:
     external: true
     name: glpi-docker-net

I wander if this happens because the credential have been changed a couple of times inside the docker-compose.yml file after the first deployment?
Thanks in advance for any given help.