Phone Issue

[Yorkie67]

Hi..my first post. I have a 4h MY18. I use a Samsung phone with Android Auto. Just recently when I end a call it won't return to the radio. It acts as though the phone still connected and nothing will disconnect it (pressing the button on the touch screen, steering wheel or disconnecting the phone). When this happens the radio won't work nor am I able to make another call. I have to switch the car off to make this phantom call stop. Many thanks in advance.