You can manually downgrade back to Firmware 2 if you experience any issues with Firmware 3.
This is done by putting the Handy into Safe Mode and using a hotspot with a special name to download the old firmware. When downgrading, the Handy will automatically look for this hotspot and connect without additional configuration.
For iOS users, please ensure the option Maximize Compatibility is enabled like the image below.
Steps
Set up a Wi-Fi hotspot on your phone with the following credentials
1.1 SSID: safemode
1.2 Password: recoveryWith your phone nearby, plug your Handy to an electric socket while keeping the Wi-Fi button pressed
When the LED pulses YELLOW, you are in Safe Mode and you can release the WI-FI button
Press and hold the DOWN button until the LED begins to fade in a rainbow fashion. This means the downgrade to FW2 is in progress. The Handy will automatically restart when the upgrade is successfully completed.