It would not surprise me if QuickSight didn’t recognize German states like it does US states. There have been a few issue with global geospatial data types.
Also, to doublecheck, have you tried the steps in the video in this topic (Kind of hard to see but you can open the video in another tab in your browser to make it bigger):
If you’ve tried this/it doesn’t work with a refresh then I can mark this topic as a feature request for the QuickSight team.