not working "Header" facet in manage books

[xarehuber]

Hi,
I've cloned the app without any changes. If I run manage books in fiori elements and try to create a book, then I have a header facet which keeps identical fields to the general facet.

If I enter values in one of the fields then it's derived to it's "clone". If I enter a author-name in the header, then I get weird error-messages I can't get rid of. I think this whole header-facet should be removed, because it's not needed and not working.

Regards
Markus