problem relation User <--> Article:Class App\Nova\Article not found

I created a 1 to n relationship between User and Article.

Model User:

public function articles()
{
    return $this->hasMany(Article::class);
}

Model Article

public function articles()
{
    return $this->hasMany(Article::class);
}

in Resource Nova I created Articles for Article, while the one for users is already defined:

Resource Articles:

public function fields(Request $request)
{
    return [
        ID::make(__('ID'), 'id')->sortable(),

        Translatable::make([
            Text::make('Title'),
            Trix::make('Body'),
        ]),

        DateTime::make('created_at'),
        DateTime::make('updated_at'),
        BelongsTo::make('User'),

        Text::make('img'),

    ];
}

and here the relationship works.

while User side does not work:

Resource User:

public function fields(Request $request)
{
    return [
        ID::make()->sortable(),

        Gravatar::make()->maxWidth(50),

        Text::make('Name')
            ->sortable()
            ->rules('required', 'max:255'),

        Text::make('Email')
            ->sortable()
            ->rules('required', 'email', 'max:254')
            ->creationRules('unique:users,email')
            ->updateRules('unique:users,email,{{resourceId}}'),

        Password::make('Password')
            ->onlyOnForms()
            ->creationRules('required', 'string', 'min:8')
            ->updateRules('nullable', 'string', 'min:8'),

        HasMany::make('Article')
    ];
}

When I go to User I get the following error:

Class App\Nova\Article not found