Custom falMedia field for tx_news

Question

I'm trying to implement a custom media field 'fal_more_media' in tx_news, according to the manual here https://docs.typo3.org/p/georgringer/news/main/en-us/Tutorials/ExtendNews/ProxyClassGenerator/Index.html

Simple text fields work fine but I can't get any output when using this syntax for additional FAL Media items, the getFalMoreMedia() Function always returns an empty result.

this is what I've got in /typo3conf/ext/newsextend/Classes/Domain/Model/News.php

namespace Stiller\Newsextend\Domain\Model;

class News extends \GeorgRinger\News\Domain\Model\News
{
   
   protected $falMoreMedia;
   
   public function __construct()
   {
        $this->falMoreMedia = new ObjectStorage();
   }
   
   public function getFalMoreMedia(): ?ObjectStorage
    {
        return $this->falMoreMedia;
    }
    
    public function getMoreMedia(): ?ObjectStorage
    {
        return $this->getFalMoreMedia();
    }
    
    public function setFalMoreMedia(ObjectStorage $falMoreMedia): void
    {
        $this->falMoreMedia = $falMoreMedia;
    }
    
    public function addFalMoreMedia(FileReference $falMoreMedia): void
    {
        if ($this->getFalMoreMedia() === null) {
            $this->falMoreMedia = new ObjectStorage();
        }
        $this->falMoreMedia->attach($falMoreMedia);
    }
}

/typo3conf/ext/newsextend/Configuration/TCA/Override/tx_news_domain_model_news.php

    defined('TYPO3') or die;


$fields = [
    'fal_more_media' => [
            'exclude' => true,
            'label' => $ll . 'tx_news_domain_model_news.fal_more_media',
            'config' => [
                'type' => 'file',
                'appearance' => [
                    'createNewRelationLinkTitle' => $ll . 'tx_news_domain_model_news.fal_more_media.add',
                    'showPossibleLocalizationRecords' => true,
                    'showAllLocalizationLink' => true,
                    'showSynchronizationLink' => true,
                ],
                'behaviour' => [
                    'allowLanguageSynchronization' => true,
                ],
                'inline' => [
                    'inlineOnlineMediaAddButtonStyle' => 'display:none',
                ],
            ],
        ],              
];

\TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addTCAcolumns('tx_news_domain_model_news', $fields);
\TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addToAllTCAtypes('tx_news_domain_model_news', 'fal_more_media');

What is missing? In the TYPO3 Backend the field is displayed and I can add media files as intended. see also Access Images in new field with sys_file_reference in tx_news