You're great. Thanks you for your advice and patience.
That's indeed the reason. If I deactivate my KIS 2016, I get results from amazon_de.
Now I have to find out, which settings I have to change in KIS 2016... (so this seems to be a new problem for me
)
Edit: I found the settings in KIS 2016 (to controll programms), so now KIS 2016 should "trust" calibre in every way.