Error deleting page with virtual grandchildren about kirby HOT 4 CLOSED

<?php
class ArtworkPage extends Page
{
  public function children(): Kirby\Cms\Pages
  {
    $images = [];
    
    
    if($image = $this->mainImage()->toFile()):
      $images[] = [
        'slug'     => $image->name(),
        'num'      => 0,
        'template' => 'lightbox-image',
        'model'    => 'lightbox-image',
      ];
    endif;
    

    if($this->additionalImages()->isNotEmpty()):
      foreach ($this->additionalImages()->toFiles() as $image) {
        $images[] = [
          'slug'     => $image->name(),
          'num'      => $image->sort()->value(),
          'template' => 'lightbox-image',
          'model'    => 'lightbox-image',
        ];
      }
    endif;

    return Pages::factory($images, $this);
  }
}

<?php

class LightboxImagePage extends Page
{
  public function image(string $filename = null): Kirby\Cms\File|null
  {
    if (!$filename) {
      return $this->parent()->images()->template('image')->findBy('name', $this->slug());
    }

    return parent::image($filename);
  }
}

<?php
class ArtworkPage extends Page
{
    public Pages|null $children = null;

    public function children(): Kirby\Cms\Pages
    {

        if ($this->children instanceof Pages) {
            return $this->children;
        }

        $images = [];


        if($image = $this->mainImage()->toFile()):
          $images[] = [
            'slug'     => $image->name(),
            'num'      => 0,
            'template' => 'lightbox-image',
            'model'    => 'lightbox-image',
          ];
        endif;
        
    
        if($this->additionalImages()->isNotEmpty()):
          foreach ($this->additionalImages()->toFiles() as $image) {
            $images[] = [
              'slug'     => $image->name(),
              'num'      => $image->sort()->value(),
              'template' => 'lightbox-image',
              'model'    => 'lightbox-image',
            ];
          }
        endif;

        return $this->children = Pages::factory($images, $this);
    }

}