Propery does not validate with eloquent mutator

On User model, I have a mutator:

public function setPasswordAttribute($password)
{
    if ($password != null && $password != '') {
        $this->attributes['password'] = bcrypt($password);
    }
}

Validation rules on User component:

class Users extends Component
{
    ...

    public User $editing;

    public function rules()
    {
        return [
            'editing.name'  => ['required', 'string', 'max:255'],
            'editing.email' => [
                'required',
                'string',
                'email',
                'max:254',
                Rule::unique(User::class, 'email')
            ],
            'editing.password' => ['required', 'string', 'min:8']
        ];
    }

    public function save()
    {
        $this->validate();      // Password rule not validate here
        $this->editing->save();
        $this->showEditModal = false;
    }

    ...
}

Steps to Reproduce:
When create an user and click save, ‘editing.name’ and ‘editing.email’ was validated sucessful, but password rule does not work anymore, example ‘length’ does work, I can create an user with short password ‘123’.

Livewire version: 2.3.1
Laravel version: 8.14
PHP version: 7.4.12

Any ideas why does it not work? Thank you.