Before updating your device, did you fully charge your device or make sure it has at least 10% battery left. You need to make sure your phone screen is on and do not perform other operations on your phone during the upgrade.
For Android mobile device, please try the following:
1. Enable auto-start and lock Mi Fit App in the "Recent Apps"/ "App overview" plane.
2. Erase Bluetooth Share Data and app caches
3. Reboot your phone and switch network between WiFi and 3G/4G
4. Sign out of Mi Fit app and log in again. When you open the app, the app will connect with the watch and update automatically.
For the iOS mobile device, please check the below:
1. Go to your phone's Bluetooth setting and remove the Amazfit device. To do so, tap on the icon next to the Amazfit and tap Forget this device.
2. Reboot your phone
3. Restart the app to connect and update
If it still doesn't work, please uninstall/reinstall the app >> Reboot your watch and your phone >> Restart Mi Fit app to see if the app will show update automatically.
If you still have the same issue, please contact firstname.lastname@example.org