(Can't search for "two" on this forum, but "simultaneous" returned nothing, apologies if discussed before).
I swear I somehow, once, had one cellphone connected as audio, and the other as a phone in my 2013.
The behavior was that the audio was streaming from phone 1, and a phone call made with phone 2 interrupted it and took over the audio system.
This was quite elegant, and I've been trying to figure out how to recreate it.
Has anyone discovered the pairing / connection sequence that leads to this? (Note: it's not possible on Android to configure BT as "phone without also having it be "audio"; though "audio" without "phone" is possible. And, the phones were both configured for both when this happened.)