At the end of each sleep session, your sleep analysis data should automatically be synchronized to your iPhone.
In case that fails please follow these recommendations:
Make sure you have installed the latest version of iOS and watchOS
This ensures that you are running the most current version of all software components that could be responsible for this issue.
Make sure your devices are properly connected with each other
Pillow on the Apple Watch and the iPhone communicate via Bluetooth and/or wifi. If you have enabled Airplane mode or disabled Bluetooth or wifi automatic synchronization will not work. Also, make sure both devices are within 10m between each other.
Try synchronizing your sleep data manually
Pillow offers the option to synchronize your data manually.
To do that:
Make sure both devices are properly connected with each other (as described above).
Open Pillow on your Apple Watch
Scroll down and tap on the "Settings" button
Tap on "Synchronize data"
Restart your devices
Restart your Apple Watch and iPhone and try synchronizing again.
Recommendation
When you use Pillow on the Apple Watch and the iPhone together (for alarm or audio recordings), it is strongly recommended to start and stop the sleep session from the Apple Watch.
If the problem persists please contact our support team to help you right away.