Downloaded Music and Audiobooks disappear

[D-Dave]

Today, while listening to an audiobook, playback suddenly stopped. When checking ibooks, all my audiobooks (20+) have disappeared...when trying to play some music till I get home to resync audiobooks back on the Phone I see that all downloaded music is gone as well...
As this has happened twice before in the last couple of Month and is rather annoying (takes 2-3 houres to get everything back on the phone) I could use your help...
iPhone is the 6s, iOS is 9.3.2 and there is 30GB of free space when all audiofiles are synced on the device...
Has anyone experienced the same and/or has any workaround ?
P.S. Apple Support is not helpful in any way....

 

[dawindmg08]

Add me to the list. This has happened to me at least twice now on my 6s that I got a few months ago. I'll go to play some music in my car and POOF -- all the music that was there the last time I checked has now disappeared. All my Playlists disappear too and get replaced with what looks like the defaults when you first open iTunes (Classical Music, My Top Rated, Recently Added, etc.)

If I plug in the phone and open iTunes, it shows all the music that SHOULD be synced to it, but if I double-click on one of them then an exclamation point shows up next to it. Meanwhile in the colored storage bar at the bottom, it tells me that there's barely any music on there (9 songs instead of 490). If I sync it then it starts copying songs back to the iPhone -- so it really seems like they were deleted.

I did sign for Apple Music back when it was a free trail, but cancelled it once it reverted to paid. I don't know if that has anything to do with it, but the Phone's behavior when this happens leads me to suspect it. Both the Music app and System settings revert back to what a Music subscriber might see.