Why can't the current phone reconnect and why is the Mi Fitness APP not showing the Xiaomi Smart Band 9 when multiple phones are logged into the same Xiaomi account?

Here are some reasons and solutions for this issue:
1. The current phone cannot reconnect because the old phone has unbound the device and the new phone has not synchronized the account. Therefore it cannot reconnect to this device;
2. Check which screen the band is displaying. If it's on the QR code screen or language selection screen, unbind the device from the Mi Fitness APP on your phone and then re-scan to pair;
3. Make sure the [Bluetooth] icon on the band is constantly on. If it is, use the [Find phone] feature to check if it's connected to the current phone. If not, unbind the device from the APP and then rebind it with the current phone;
4. If the device is not shown on the old phone's Mi Fitness APP device management page, it means the old phone has unbound the device. After logging in with the same account on the new phone and syncing, the band will not be displayed. If the band is on the QR code screen or language selection screen, re-scan to pair;
5. When connecting the band to two phones using the same Xiaomi account, after resetting the band, pair it again with the new phone and turn off Bluetooth on the old phone. If the new phone still cannot reconnect, it is because the new phone did not automatically retrieve new login and pairing information.