Mike took Leo's advice and is recording with his iPhone. He also uses Hey Siri for turning on Do Not Disturb mode. But now Siri requires him to unlock the phone to enable Do Not Disturb. Leo says that an update may have closed a bug that allowed it. He should be able to access it via the lock screen. Welcome to the world of Apple where they know better than we do and make changes that we'll just have to learn to live with. It may also be that Mike is using the beta of iOS 10. Features will often not work in a beta.