Same Attributename on different PLM Objects in Bookmark Folder are not working

I have an Issue with the Bookmark Folder App. I've created an Attribute "Titel 2" on Pyhsical Products and the same Attributename on Documents. Now when I check the Bookmark Folder App, the Attribute is shown for Physical Products, for Documents is not working.
There are System Attributes like "Description" and this is working for different PLM Object Types. Why is this not working with Custom Attributes? For better understanding check Screenshot.

Thank you.