Why can't the Xiaomi Smart Band 9 Pro’s Bluetooth be found when pairing?

The Xiaomi Smart Band 9 Pro’s Bluetooth can have been paired with another device, or the band was previously paired, but the pairing information was not cleared from the phone.
For your reference, you can troubleshoot as follows:
1. Restart the Mi Fitness APP, toggle Bluetooth off and on, then try adding the device again;
2. Please check the APP's region;
3. Check if the band’s Bluetooth information appears in the phone’s Bluetooth list. If so, remove it before rescanning to pair;
4. On the band’s binding page, swipe up to enter the settings page, perform a factory reset, and then scan again to pair from the QR code page;
5. Restart both the band and phone, or try pairing with a different phone;
6. If previously paired with another phone, turn off Bluetooth on that device.