DBConfig never asked for the root password when configuring mysql

I just tried to install xwiki-tomcat8-mysql on a Ubuntu bionic with mariadb already configured with a root password using mysql_secure_installation command.
During the install dbconfig asked me the information to create xwiki mysql database, but never asked the root password of my mysql installation: it always tried to connect without using any password, which never worked.
Maybe it's related to some changes on the way dbcommon work.