Hello,
here is a picture describing my problem:
As you can see its not displaying the right page name, its showing the Navbar_theme.
My slicemachine configuration page:
Any ideas on how to fix that?
Welcome to the Prismic community forum, and thanks for reaching out to us! 
From the screenshots you shared above, the name of your Custom Type is Seiten, as shown on the Type list of the first screenshot and the header of the third screenshot, while the name of your select field is Navbar Theme from the second screenshot.
It will be helpful for us if you can share more details on the issue you're facing.
Thanks,
Racheal.
Hello Racheal,
the first 2 pages created display the right field of "Name", while the last 2 pages that I created also have names like "Anfahrt" and "Kontakt" but it is not displaying the right field "Name" instead it takes for newly created "Seiten"(Pages) the field Navbar_Theme.
This is confusing for my marketing team because they do want to see the actual name of the page.
Thanks for the reply.
Marcel
Hello @c.kloster-website,
I understand that the suggested solution may seem a bit manual. However, you can easily change the document's name by clicking on the top left corner when you access the document. Please refer to the attached image below for a visual representation:
Thanks,
Racheal.