Originally Posted by
finless
Phones can only have one active pair for Music. This is why when you turn on your headset it cancels out the receiver.
Now there maybe a way out. Look in your 20S manual page 19. There is a area that talks about selective pairing.
Using that, pair HFP (Phone call only) to your 20S.
Oh, before you do that erase the current pairing you have on your iPhone and reset the BT receiver.
Make sure your headset is on and phone only mode works.
Then pair your phone to the receiver. If the receiver doesn't try to take over HFP when it pairs, you should be good to go.
Bob