It's common knowledge that bluetooth is not a strong point for the 240. Excerpt from manual:
Maintain a distance of 20 cm (8 in) between the AK240 and the paired Bluetooth device. Audio quality will degrade with longer distances, and the pairing may disconnect at a distance of 2 m (6.5 ft). (Distances may vary depending on the device and environment) Crosstalk may occur while using Bluetooth.