Laravel 8，找不到模型工厂类

so when using the new model factories class introduced in laravel 8.x, ive this weird issue saying that laravel cannot find the factory that corresponds to the model. i get this error

PHP Error:  Class 'Database/Factories/BusinessUserFactory' not found in .....

tho ive followed the laravel docs, ive no idea whats going on

Here is the BusinessUser class

<?php

namespace App;

use Database\Factories\BusinessUserFactory;
use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;

class BusinessUser extends Model
{
    use HasFactory;
}

and the factory

<?php

namespace Database\Factories;

use App\BusinessUser;
use Illuminate\Database\Eloquent\Factories\Factory;
use Illuminate\Support\Str;

class BusinessUserFactory extends Factory
{
    /**
     * The name of the factory's corresponding model.
     *
     * @var string
     */
    protected $model = BusinessUser::class;

    /**
     * Define the model's default state.
     *
     * @return array
     */
    public function definition()
    {
        return [
            'name' => "dsfsf"
        ];
    }
}

任何 idea 或线索都将不胜感激.