iOS 15: App no longer listed in iCloud settings

Since iOS 15 the app i develop is on many devices no longer listed in Settings > Apple-ID > iCloud. It used to be there. The app uses iCloud Key-Value-Storage. On some devices it is listed and on some not. I did not change iCloud related things. It seems to be something with iOS 15.

Does anyone else have this problem? How can i ensure the app is listed in iCloud settings?

iOS 15: App no longer listed in iCloud settings
 
 
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