It's something that has happened to many of us. Most likely a software issue. If it comes and goes in 2 second intervals, though, then there's a TSB to check to see if it's your backup camera.
It's been intermittent in mine since I bought it over a year ago. Every time I take it to the dealership for something I have them check for a software update. So far nothing.
A quick fix (at least for me) is to push the input button on the steering wheel (right side center button on the back of the steering wheel). Cycle the input with that button and your audio should come back. Every time I lose audio I do that trick and it comes back.
Someday FCA may come out with a software update for us. With uConnect 5 on the horizon (and whatever modification to the infotainment system to support that expansion) we may be obsolete before our factory warranty runs out.