Hey Christoph,
I believe this issue ties back to a feature request I made a while back. It’s about having the option to select a default language for the entire app, to keep everything unified. It’s pretty odd when you set everything up in German, only to have all the automatic Glide menus appear in English or other languages.
Here’s my feature request - do give it a vote if you think it makes sense: Disable language setting/Set default language