SFSpeechRecognizer Locale other than english not working

I changed the Locale to "de-DE" (and other than english locales), but nothing is detected.
Used this Apple sample code: Recognizing Speech in Live Audio · Link

Nothing is detected, after the timeout it returns:

[Utility] +[AFAggregator logDictationFailedWithError:] Error Domain=kAFAssistantErrorDomain Code=1 "(null)"
"Error while recognition: Error Domain=kAFAssistantErrorDomain Code=1 \"(null)\""


Xcode 11.0 beta 5

iOS 13.0 beta (17A5565b)