Why can't the Xiaomi Smart Band 8 be found when paired and connected with a new phone after being unilaterally restored to the factory?

After the iOS phone is connected to the device and the device is unilaterally restored to the factory, the iOS phone system Bluetooth will try to connect back to the device, and the probability of a new phone not being found (iOS phones will always be disconnected from the device, and during the connection period, the new phone cannot be found. During the disconnection interval, the new phone is just in scanning mode and can be found). You need to enter the iOS mobile system Bluetooth, find the corresponding connected device, and ignore this device. At this time, use the new phone to search for paired connections.
When an Android phone is connected to a device and the device is unilaterally restored to the factory, the Mi Fitness APP will connect back to the device and prompt you whether to delete or add the device. At this time, the new phone cannot search for the device. Select delete the device and then use your new phone to search for a connection.