In symfony with doctrine and postgres

I have this configuration

doctrine:
    dbal:
        server_version:    '16.3'
        dbname:            'dev'
        host:              'postgres'
        port:              5432
        user:              'app'
        password:          'pass'
        driver:            'pgsql'
        charset:           'utf8'

as you can see my postgres user for connection is app

Now if I do in my controller

        $sql = 'SELECT * FROM user';
        $em = $this->getEntityManager();
        $stmt = $em->getConnection()->prepare($sql);
        $a = $stmt->executeQuery()->fetchAssociative();;

The result is app !

So doctrine is actually looking in the wrong database because it is retrieving the Postgres user and not user from my dev database

I do not understand why. Can someone shed some light ?