Laravel: ValidationException::withMessages not sending all errors

I'm trying to make some validations in Laravel. I have a resource with nested resources, so I need to validate many things at once. I have a Level, which is composed by many Questions. So In order to validate them I first validate the Level, and then each question one by one.

I use the following method:

public function ValidateDataAgainstModel($data) {
    $book = Level::ValidationBook(); // Or Answer::ValidationBook()
    $validator = Validator::make($data,
        $book['rules'],
        $book['messages']);
    if ($validator->fails()) {
        return $validator->errors();
    }
    return null;
}

That method is used in Level and Question, so it is the same. Then I group all errors in a single array like this:

$errors = [];
$errors['level'] = $levelError;
$errors['questions'] = $questionsErrors; //$questionErrors is an array of each question errors

Then to check that my array is correct I make a \Log::info($errors) and get the following result:

[2018-12-12 23:47:12] local.INFO: array (
  'level' => 
  Illuminate\Support\MessageBag::__set_state(array(
     'messages' => 
    array (
      'name' => 
      array (
        0 => 'Se requiere el nombre del nivel',
      ),
    ),
     'format' => ':message',
  )),
  'questions' => 
  array (
    0 => 
    Illuminate\Support\MessageBag::__set_state(array(
       'messages' => 
      array (
        'description' => 
        array (
          0 => 'Se requiere la descripción de la pregunta',
        ),
      ),
       'format' => ':message',
    )),
    1 => 
    Illuminate\Support\MessageBag::__set_state(array(
       'messages' => 
      array (
        'description' => 
        array (
          0 => 'Se requiere la descripción de la pregunta',
        ),
      ),
       'format' => ':message',
    )),
  ),
) 

As you can see I have two questions with errors. In order to return this to my client, when I do the following

if ( count($errors) > 0 ) {
    throw ValidationException::withMessages($errors);
}

But when the data arrives to my client, the question errors are no complete, instead of get an index with an array of the questions errors, I only got one question error.

Does anyone knows why this is happening? It seems like is grouping the errors in a single one.

via Chebli Mohamed