Access denied to create a test database

Question

I don´t understand why user is allowed to create a dev database while he is not to create a test one.

At the root of my project :

docker-compose

db:
    image: mysql:5.7
    environment:
        - MYSQL_DATABASE=${DB_NAME}
        - MYSQL_ROOT_PASSWORD=${DB_ROOT_PASSWORD}
        - MYSQL_USER=${DB_USER}
        - MYSQL_PASSWORD=${DB_PASSWORD}
        - MYSQL_ALLOW_EMPTY_PASSWORD=true
    ports:
        - '127.0.0.1:3306:3306'
    volumes:
        - 'db:/var/lib/mysql'

.env :

DB_NAME=mydb
DB_ROOT_PASSWORD=root
DB_USER=dev
DB_PASSWORD=dev

In the app directory, I tried following scenarios :

Scenario 1 :

Without .env.test and an overriden url from dev to test

doctrine.yaml :

doctrine:
    dbal:
        url: '%env(DATABASE_URL)%'
        driver: pdo_mysql
        server_version: "%env(DB_VERSION)%"

test/doctrine.yaml :

doctrine:
    dbal:
        dbname_suffix: _test
        profiling: true

.env :

APP_ENV=dev
DB_VERSION=5.7
DATABASE_URL=mysql://dev:dev@db:3306/mydb

Scenario 2 :

With the same config in both dev and test environments, except the database name

doctrine.yaml :

doctrine:
    dbal:
        url: '%env(DATABASE_URL)%'
        driver: pdo_mysql
        server_version: "%env(DB_VERSION)%"

test/doctrine.yaml :

doctrine:
    dbal:
        url: '%env(DATABASE_URL)%'
        profiling: true

.env :

APP_ENV=dev
DB_VERSION=5.7
DATABASE_URL=mysql://dev:dev@db:3306/mydb

.env.test :

APP_ENV=test
DB_VERSION=5.7
DATABASE_URL=mysql://dev:dev@db:3306/mydb_test

Scenario 3 :

With different variables in different environments

doctrine.yaml :

doctrine:
    dbal:
        url: '%env(DATABASE_URL)%'
        driver: pdo_mysql
        server_version: "%env(DB_VERSION)%"

test/doctrine.yaml :

doctrine:
    dbal:
        url: '%env(DATABASE_TEST_URL)%'
        profiling: true

.env :

APP_ENV=dev
DB_VERSION=5.7
DATABASE_URL=mysql://dev:dev@db:3306/mydb

.env.test :

APP_ENV=test
DB_VERSION=5.7
DATABASE_TEST_URL=mysql://dev:dev@db:3306/mydb_test

Problem :

docker compose run --rm myContainer doctrine:database:create : the main database is created without problem

docker compose run --rm myContainer doctrine:database:create --env=test : I always get the following error :

Could not create database mydb_test for connection named default An exception occurred while executing a query: SQLSTATE[42000]: Syntax error or access violation: 1044 Access denied for user 'dev'@'%' to database 'mydb_test'`