Laravel project fails to connect to database when using PHP artisan serve but works with MAMP

I have a Laravel project set up on my MacBook and I’m encountering an issue with connecting to the database when using PHP artisan serve. Here’s the problem:

When I access the project via localhost/project_name/public, everything works fine, and database connection is also working fine.

However, when I try to use php artisan serve and access the project via http://127.0.0.1:8000 or http://localhost:8000, I encounter the following error:

Here are the relevant sections of my configuration:

.env File

DB_CONNECTION=mysql
DB_HOST=localhost
DB_PORT=3306
DB_DATABASE=my_db
DB_USERNAME=root
DB_PASSWORD=root

database.php file

'mysql' => [
    'driver' => 'mysql',
    'host' => env('DB_HOST', '127.0.0.1'),
    'port' => env('DB_PORT', '3306'),
    'database' => env('DB_DATABASE', 'forge'),
    'username' => env('DB_USERNAME', 'forge'),
    'password' => env('DB_PASSWORD', ''),
    ...
]

Here are the troubleshooting steps I’ve already taken. But nothing works for me

1.Cleared configuration cache using commands like

php artisan config:clear 
php artisan cache:clear 
php artisan config:cache 
php artisan optimize

2. Deleted the cache files located at /bootstrap/cache/.
3. Tried changing localhost to 127.0.0.1 in the .env file.

Note: I am not using MAMP’s default ports. Instead using 80 & 3306

Despite these attempts, the issue persists. I suspect there might be a configuration issue with MAMP or my macOS settings. Can anyone suggest a solution or further troubleshooting steps? Any help would be greatly appreciated. Thank you in advance!