2013 Hyundai Elantra + iPhone + Bluetooth Phone Call/Music Streaming issu

I have a 2013 Elantra and an iPhone 6 (with the latest iOS) that I connect via the Hyundai USB cable.

I listen to music over the cable, and make/receive phone calls over Bluetooth.

I have an issue when I'm listening to music and receive a call.

When I answer a call, I can hear and talk to the caller, but the music continues to play at the same time. Making the phone call almost impossible to understand.

If I unplug the USB cable during the call, it SHOULD immediately stop the music, as that's how it's playing. But that doesn't happen. Music continues to play in the background of the call.

So for some reason, when getting a call, music playback is switched from USB and Bluetooth. I have to manually close the music app on my phone, while driving, in order to understand my caller. Dangerous. Distracting.

If I'm listening to the Podcasts app instead of music, this behavior doesn't happen. Podcasts stop when I answer the call. Continue when I end it.

Also if i PLACE a call, instead of receiving one, it works as it should. Music stops until the call is finished.

I've paired/re-paired my phone multiple times, but the problem still persists.

Thanks for any help and suggestions,