Laravel php artisan serve dose not respect env flag

I'm working on a Laravel Project and try to integrate Laravel Scout. For testing with dusk I have created a .env.dusk.local environment file, that is used for testing. But when I try to run php artisan serve --env=dusk.local it just runs the default .env file. Also all other .env files don't work.

Im using Laravel 8.15.0. I also try clearing the config cache but nothing changed.

I'm currently out of ideas, so hopefully someone can help me.