Hello, as everyone knows, the latest iOS 9 beta now includes the new Music app with Apple Music support. Yesterday I made all of my tracks available offline via a playlist that contains all of my songs. At the top it said "xxx songs are downloading" (or something along these lines, my iOS is not set to English), and after that was done, I was able to listen to all of them with Airplane mode enabled. Today I got into my car and started my Apple Music playlist (it only contains songs I got from Apple Music). A few tracks were playing, but it turned out that around 80 of the overall 90 tracks went grey. So a few were still there, but the majority basically disappeared. I blocked the Music app for mobile data usage to save my data plan. What happened there and how do I prevent it in the future?