Please try to force quit Pillow on your device and reopen it. Make sure that your Watch and Phone are in range and try again.

To force quit Pillow, on an iPhone X or later, or an iPad with iOS 12 or later, or iPadOS, from the Home Screen, swipe up from the bottom of the screen and pause slightly in the middle of the screen. On an iPhone 8 or earlier, double-click the Home button to show your most recently used apps.