Please refer to the following steps to troubleshoot:
1. Ensure that Bluetooth is enabled on both your phone and the band. Try turning Bluetooth off and on again, and reconnect the devices;
2. Go to your phone’s settings and check that the Mi Fitness APP has the appropriate permissions for Bluetooth, storage, and background activities;
3. Reset to factory settings to clear old data. Update the Mi Fitness APP to version 3.35.0 or above on Android, or 3.29.0 or above on iOS. Future exercise records will sync to the phone properly.