I have found that when I plug in my USB stick (with music on it) my uConnect does not work with my phone. This is in a 2017 Fiat Abarth. I had the same issue in my 2015 Abarth. Is there a fix to this?
Move all your music to your phone memory card assuming you've not got a I phone (Apple in their wisdom charging £100+ for memory that costs a few £'s ) perhaps?