It could be for the following reasons.
1, the Bluetooth headset may have no power, or the power is relatively small. At this time, it is necessary to charge the Bluetooth headset in time, and then reconnect with the Xiaomi mobile phone after it is charged. 2, Bluetooth headset and millet phone may not be connected, this situation can directly millet phone and Bluetooth headset for re-pairing.
3, maybe the media volume of the millet phone itself is relatively low, directly turn up the media volume of the phone.
4. The distance between Xiaomi phone and Bluetooth headset is too far. If the distance is too far, there may be no sound, and the distance between the two is closer when the Xiaomi mobile phone and the Bluetooth headset are used.