BLE detection problem during a phone call

I am experiencing a problem with BLE devices detection when an iPhone is connected through BLE with a car during a phone call.

My application needs to detect and connect to a BLE device to interact with it. When the iPhone is connected through BLE with a car and a call is ongoing, the app is not able to detect the BLE device. As soon as I hang up, the app immediately detects the BLE device and can interact with it. When I tried to use Nordic's NRF Connect I had the same behaviour. The app didn't detect the advertising of any BLE devices during a BLE phone call, but when I hang up it start detecting the BLE devices.

I verified this behaviour with Subaru and Ford Ranger.

Do you have any ideas on what the problem may be?
BLE detection problem during a phone call
 
 
Q