Why can’t my iOS phone connect to Xiaomi Smart Band 8 after clearing the app in the background?

Open the Mi Fitness App to confirm whether the connection can be restored normally; if it cannot be connected, click the connect button to see whether it can be connected normally; if it cannot be connected, confirm whether the device is connected in the Bluetooth of the mobile phone system. If the device is connected, ignore it. The device confirms whether the connection is normal; if the device is not connected, the device will be restored to factory settings and the Mi Fitness App will rescan to connect to the device.