I've had the exact same problem since I changed to a Samsung Galaxy S5. It's been to the dealer about 4-5 times. Their final answer: it's incompatible software and there's nothing we can do.
Gee, that's great, thanks!
I've been so turned off by this experience that I haven't ever used the system for music, voice command, etc.
On the other hand, over the summer I rented a new Durango and everything worked perfectly with both my S5 and my wife's LG.