Panasonic - Telephones - KX-TGD890, KX-TGD892, GF892, TGDA99 - Will not disconnect from Bluetooth.

Panasonic telephones KX-TGD890, KX-TGD892, KX-TGF892, KX-TGDA99 have the ability to connect to a Bluetooth headset so that you can use the headset to speak and listen on a call. If you are also using the Bluetooth headset for another Bluetooth function (listening to music) after the call is complete the Panasonic telephone should disconnect and allow you to continue use of the other device. If this does not occur you may need to disconnect the device manually.
This video will show you two options to disconnect the telephone.
Note: Disconnecting does not erase pairing.