my wife's has a 2015 chevy traverse. Sometimes when she starts the car up the a/c won't come on. she turns off the key and the engine continues to run for a short while. when she starts it up again it all goes back to normal. It is happening more and more now. we recently had the air conditioning repaired (evaporator coil), and when we got it back the radio wouldn't show any xm information for a few days. not sure if that was done then could be related.

 

Could be as the evaporator is what does the cooling, by the expansion of liquid to gas. The tech might have messed up the radio as there is lots of wiring under the dash.