Siri shortcuts work on iPhone, but not on HomePod

Question

I’m working on app that uses Siri Shortcuts, and I’ve met one strange issue: If I run a shortcut on iPhone, it works well. If I do the same with HomePod, connected to the same iPhone, I get “There is a problem with your app” from Siri. My shortcuts are created within the app.

if #available(iOS 12.0, *) {
    let activity = NSUserActivity(activityType: command.rawValue)
    activity.title = selectTitle(activityType: command)
    activity.isEligibleForSearch = true
    activity.isEligibleForPrediction = true
    activity.persistentIdentifier = NSUserActivityPersistentIdentifier(command.rawValue)
    responder.userActivity = activity
    activity.becomeCurrent()
}

Any ideas how to make them work via HomePod? Thanks in advance!