The phone screen lighting up during this action is due to the following reasons:
1. The Xiaomi Smart Band 9 Active preloads certain APPs or widgets in the left and right interface screens. For example, when you slide left or right to access the music widget, the band preloads the music interface to ensure quick access. This process will temporarily trigger the phone to search for the connected device, causing the phone screen to light up;
2. During this preloading process, the phone actively searches for the connected band, which can cause the phone screen to briefly turn on as the phone is trying to establish a connection. This is a normal behavior;
3. If you do not frequently use the music widget, you can replace it with other widgets that you use more often in the Mi Fitness APP. This will prevent the phone screen from lighting up when sliding left or right on the widget interface.