CoreLocation/CoreBluetooth Interference in Subaru Vehicles

We are currently developing a vehicle mileage tracking solution utilizing BLE beacons to initiate location tracking for mileage estimations. We've noticed that in newer model Subarus when connected to the vehicle's Bluetooth calling system and while making a call, CoreBluetooth is unable to receive didDetectDevice notifications. As soon as the call is ended, the beacon is detected on its next broadcast. Streaming music over the vehicle's speakers does not cause any issues. I'm wondering if anyone else has seen similar behavior or would be able to shine a light on the potential reason for something like this to happen.