Ironically, i started experiencing similar Apple Music issues earlier this week. Many Apple music songs disappeared from playlists on my phone. Additionally 95% of my playlists dupped displaying "_1." Then all of sudden i started getting an error about my iCloud Music Library, stating: "iCloud Music Library can't be enabled. You can enable it later from Music in Settings. Until then, your music won't be available on your other devices." What's odd is those deleted songs still appear in my library on iTunes my mac but were somehow magically deleted from playlists both on my phone and mac.
Chatting with Apple Support but it appears that iCloud has been having issues. Anyone experiencing similar issues with their Music/Apple Music playlists?