If your Bixby language is a German, it is usually not released here in UK. Bixby language will depends on the place where your phone was originally released. I sincerely apologise since there are no option to change the language.
If you are planning to reflash the device, it will remove the Samsung services and may tend to errors or unsupported Samsung services in rooted device. Rooted devices will be called to those device's software that has been modified.