bluetooth disconnects during call

My iPhone X connects to my car’s Bluetooth just fine when playing music. If I make or receive a call, after one minute the Bluetooth connection is lost. Even when the call is done, the car won’t pair again to the phone until I turn the car off and restart it. Toyota says it’s the phone. Anyone else have a similar issue? What can I do? If I’m on a long drive and get a call, I’ve lost both the call and ability to listen to music the rest of the trip unless I pull over and restart the car.