Yes! I am having the exact same issue in the Cape Coral, FL area; it's been about the last three to four weeks... I am unable to recall if it started before or after the upgrade to iOS 9. However, my wife and I are having the exact same issues between many devices. Her iPhone 5S and my iPhone 6, and then since upgrading, my iPhone 6S and the iPhone 6 restored to her profile and with a new SIM. All four configurations are having the same issue, I am also getting 15-20 mbps down speeds on my AT&T LTE network, and have no issue streaming Beats 1 (which seems to be a similar bitrate to the on demand songs of the rest of Apple Music). Songs in both playlists, my library, or even the preconfigured Apple Music Radio stations all try to stream a song.. often hang, or start to play about 2-5 seconds worth.. and then completely cut out. On occasion they will start up again about 20 seconds later.. but usually only get another 3 seconds out before cutting out again. It's absolutely infuriating. Over the wifi at my house, which is actually slower and more inconsistent than my LTE connection, I can download entire albums in seconds. Anecdotally, when I got my new phone last week, I turned the wifi on in off after restoring to download all of my apps over LTE, because my modem kept on crapping out over the multiple connections (this is another story, but proves that my LTE data connection to some Apple services is otherwise sound). Curiously, I have noticed mildly better luck in downloading songs that I have uploaded to my iCloud Music Library via iTunes Match, which are not in Apple's library, over LTE.. but this is not a sure thing either.
I have attempted to log out of my iTunes store account, reset the network settings on my device, toggle cellular on and off, as well as apple music's app specific cellular data toggles, and the high quality setting, with no change in the behavior. My wife's phone uses her own Apple Music account tied to mine by the iCloud Family plan. A month ago, this stuff worked great.. and while I can download music at home and then listen in the car, 90% of my music listening is during commutes and road trips, and the flexibility of being able to call upon random playlists and albums on a whim is the main reason I want to fork $15 a month to Apple for this. I'm unsure if this is some sort of server side issue, a bug in iOS regarding Cellular connections, or AT&T throttling the specific servers that contain the Apple Music files.. but something needs to be done about it.. especially now at this time when