Why doesn't INInteraction.deleteAll work on INVoiceShortcutCenter shortcuts?

In a previous version of an app, we donated some Siri Shortcuts - or rather, added them to the INVoiceShortcutCenter via:


INVoiceShortcutCenter.shared.setShortcutSuggestions(array)


Others were donated via creating an INInteraction and then calling interaction.donate() - like this:


let interaction = INInteraction(intent: intent, response: nil)
    interaction.donate()


Now, in an upcoming version of the app, we want to remove these shortcuts as they no longer are valid.


I've tried calling INInteraction.deleteAll and it only deletes shortcuts donated via the second method. Shortcuts created via the first method are not removed. I checked also (iOS12 device) under My Shortcuts, the shortcuts created by using INVoiceShortcutCenter are not listed, so, why won't hey go away?