Did you purchase the 2015 as a used model? Perhaps the previous owner still has his phone connected and set up as the primary phone? Have you tried deleting everything and reconnecting with your phone? Does your phone find the car sync OK, and have you given it permission to always connect?
Yes, there are replacement radios from aftermarket sources which can be adapted to use the steering wheel buttons. I am sure you could hook up a rear camera also, but not sure if you could use the factory cable to do so. Check Crutchfield, Best Buy, or some of the other large electronic outlets to see what can be used. https://www.crutchfield.com/S-KXX5R5y4umw/
There is also a brand which several owners have used on the forum. I can't recall the name of it, but I think Walt was a representative many of them dealt with to build a system which works well. Not sure what year models it fits, so you will have to search the forum for more information, unless I can remember the name of the radio.