I setup a test environment with Wikibase client, everything seems tobe working fine, so I tried to move to the next step by importing data.
I wanted to import in this test environment a DB backup from my current production Wikibase so I read the "Can I migrate from another Wikibase installation to WBS Deploy?" paragraph, but I think the instructions are a bit tight there.

First of all, I found myself unable to access the MariaDB server. Every time I try to run the MySQL client with the docker exec command I keep receiving a "ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)".
Because of the MYSQL_RANDOM_ROOT_PASSWORD: yes setting, I know I should have found a password in the MariaDB's container log, but I was unable to find it also following instructions here https://dev.mysql.com/doc/refman/8.4/en/docker-mysql-getting-started.html#docker-starting-mysql-server . So I modified the .env and docker-compose.yml to use custom root password (not good security practice, I know, but this is only for testing): it was successfully set (properly shown using ENV command) but still I can't access. Also using the less privileged user set in .env for the Wikibase database results in the "access denied" error as above.

Can anyone help with this two issues? Thanks in advance