Laravel: Access denied for user 'forge'@'localhost' (but no such user is used in the app)

I've a Laravel application that works well but for some strange reason there is a lot of strange messages in log files:

[2019-10-04 10:24:21] production.ERROR: SQLSTATE[HY000] [1045] Access denied for user 'forge'@'localhost' (using password: NO) {"exception":"[object] (Doctrine\DBAL\Driver\PDOException(code: 1045): SQLSTATE[HY000] [1045] Access d enied for user 'forge'@'localhost' (using password: NO) at /var/www/html/pzw_prod/vendor/doctrine/dbal/lib/Doctrine/DBAL/Driver/PDOConnection.php:31, PDOException(code: 1045): SQLSTATE[HY000] [1045] Access denied for user 'forge'@'l ocalhost' (using password: NO) at /var/www/html/pzw_prod/vendor/doctrine/dbal/lib/Doctrine/DBAL/Driver/PDOConnection.php:27)

The thing is, I'm not connecting to database with user named forge. My .env uses completely different logins. And, I repeat, everything works fine: communication with database works as expected. Data is being successfully read and written.

So... why this message in log files?

via Chebli Mohamed