There are roughly three reasons for this problem. Please check the following operation in turn :
① Make sure you switch to the"TX" Mode or "RX" Mode
② If there are other Bluetooth receiving devices around, please turn off.
③After you have checked the above two reasons, it is recommended that you first turn on the Bluetooth receiving device (such as a headset) and make sure it is in a state waiting for Bluetooth matching. Then turn on the Bluetooth adapter, double-click the Bluetooth adapter's quick match button, and then bring the two closer together to successfully match.