iOS 10 changes how you use the Home button to unlock your iOS device from the Lock screen. Previously, you could unlock it by merely resting your finger on the Home button when the Lock screen was showing. In iOS 10, however, you must press the Home button and then use Touch ID to unlock the device. With newer iPad and iPhone models, Touch ID reads your fingerprint so quickly that you can usually press the Home button instead of just resting your finger on it. However, this new behavior may be disconcerting with early Touch ID-enabled devices, such as the iPhone 5s, which take longer to read a fingerprint. To revert to the previous behavior, go to Settings > General > Accessibility > Home Button and enable Rest Finger to Open.