I live in an area with poor mobile reception. I download songs from Apple Music to my iphone and can listen back. When I take my phone in the car, I can listen to downloaded music for a while but then suddenly it stops and the songs are unavailable. I get a message to sign into iTunes but this fails as it doesn't connect to the internet over cellular. I'm convinced that the phone attempts to call 'home' to Apple to check my account, it fails as I'm not getting cellular reception and so it somehow stops downloaded songs from being played. When I get home I have to download the songs again. Anybody else experience this? If it a glitch I can live with it untill fixed, if it's a designed security check then it's useless for me and makes Spotify the only alternative.