might be a loose connection or buggy software --- I had a 24 hour period where the 2010 x5 would not recognize my iphone (or my wife's) plugged into the snap-in adaptor. Worked fine with the y cable, though. I tried removing an reinstalling the snap-in adaptor a couple times. Tried shutting off car (e.g. locking car and walking away in a huff for an hour) and coming back. Problem went away the next day.

In the past month, I have had the: 1) urea needs replenishing warning at 1000 miles and above freezing weather (went away on restart); 2) iphone connection failed for 24 hours (went away the next day); and check engine light at 2000 miles (went away after letting car sit and a restart) - so this could just be infamous BMW gremlins...