When the Mi Fitness APP is running in the background APP of a third-party phone, it will be removed from the background if there is no connection for a long time, resulting in the APP being unable to reconnect to the Xiaomi Smart Band 10 when the band is turned on or returns to the connection range. In this case, it is recommended to manually start the APP to restore the connection with the band.
For your reference, here are more details about the device can not reconnect to the APP:
1. Some non-Xiaomi phones have stricter Bluetooth background restrictions, causing the connection to fail after long periods of disconnection or after powering off the band;
2. The app can lack necessary permissions like location access or background activity allowance, which are essential for stable Bluetooth reconnection.