What to do if synchronization between the Mi Fitness APP and the Xiaomi Watch 2 fails?

For your reference, here are some methods to resolve this issue:
1. Check the network connection on your phone. If your phone's Wi-Fi is disconnected, try reconnecting. If your Wi-Fi is fine, however, you still can't sync, use your mobile data;
2. Check the connection status between the watch and the phone, ensure the Bluetooth function is normal, and try refreshing the APP multiple times;
3. Please check if the Mi Fitness APP and watch firmware are up to date. If not, try updating first;
4. You can restart Bluetooth on your phone and try restarting the watch.