Laravel Eloquent save gives me more columns back

I do make an update of one entry (eg. table data) in laravel 5.7.

In my Database/model/Data.php:

 /**
 * @var array
 */
public static $titleEntity = [
    'id',
    'title'
];

In my Controller

$data = Data::ofEntity('', Data::$titleEntity)
        ->where('id', $id)
        ->first();

$data->title = 'new title';
$data->save();
return json($data) //short version

the model has more attributes and I get back:

$data->title;
$data->text;
$data->update_time;
return json($data); //short version

I only want to return like my $titleEntity.

$data->title;

Why is my save/update function of laravel returning more entries not ony the $titleEntity?

via Chebli Mohamed