If Philips Hue devices lost connection to the Home App, follow these steps: Check after every step if the problem is resolved.
- Completely close the Home App and open it again
- Turn the WLAN on the smartphone or tablet off and on
- Restart Philips Hue Bridge
- Logout and login again to the Home App
- Restart the Internet-Box
- Reset the Philips Hue Bridge and pair it again