Carplay + Pioneer + 6S = Nothing

I've seen a few similar problems mentioned in the forums, but nome of the suggestions make a difference.

I've a brand new SPH-DA120 (AppRadio4) and a 6S on 9.2.1

The 6S doesn't even charge when connected.

Using other family devices (all on 9.2.1) :

5C - full CarPlay

2 x 5S - charges, but no CarPlay

iPad Pro - registers as iPod

I've reset settings, I've even wiped and set up as new. Used diff cables. Nothing making a difference.

Stereo Firmware up to date.

What'll really bake your noodle, is that my son has a really simple JVC iPhone compatible car stereo - my 6S & the 5C work like a charm on it, the two 5S phones don't register, even after reset (I borrowed a third 5S reset it - and it worked!?).

I'm tempted to go on a CarPlay rant here, but I do want to try and fix this specific problem. Any help really appreciated...