Laravel was displaying to me \"Access denied for user \'homestead\'@\'localhost\' (using password: YES)\". One solution for this was clearing the cache and the config cache
You may need to clear the autoloader with composer dump-autoload
composer dump-autoload
If that doesn't work you can manually remove the following non-tracked (usually) files to clear the autoloader and cache if they get jammed up:
/bootstrap/cache/packages.php
/bootstrap/cache/services.php