If your Go doesn't detect sleep when you're sleeping, it's probably because you haven't specified in the app that you're wearing your Go at the wrist. If that's the case, your Go won't be able to track your sleep. To update this, perform the following steps:

1. Open the Withings App.
2. Tap My devices.
   If your Go doesn't appear in My devices, you need to install it.
3. Tap Go.
4. Tap Change how you wear your Go.
   
5. Select the appropriate option and validate.
   

If you still encounter issues, reach out to Customer Service by clicking the Contact us button at the bottom of the page.