Displays post on related project page

I’m just creating a blog section on my website. On every post page, I can choose related projects pages. That all works fine. Now I want on every project page a list of posts where this project is selected. Currently, it won’t work. Can Somebody help me what I did wrong?
At blueprint at the Post:

            type: pages
            query: kirby.page("portfolio").childrenAndDrafts
            subpages: false
            value: "{{ page.uuid }}"
            multiple: false
              back: black 

The php content at the project

      <?php foreach ($site->find('aktuelles-und-neues')->children() as $related): ?>
        <?php if ($related->projekt()->uuid() === $page->uuid()) : ?>
          <a class="link" href="<?= $related->url() ?>"><?= $related->title()->escape() ?></a>
        <?php endif ?>
      <?php endforeach ?>

Thanks for your help

I assume this is a pages section? A pages section doesn’t support queries, though. You would have to use the pagesdisplay or the pagetable plugin.

Thanks, now it work.