A trick to keep syncing offline playlists on iPhone/iPad:

1. Press play on a song in a playlist
2. Press the little i at the left top
3. Turn repeat on (this will repeat the playlist)
4. Now select all the playlists you want to have available offline

Because the playlist is on repeat, Sporify stays active and you can sync all the playlists you want without worrying about Sporify pausing the syncing because Spotify is idle.

I came up with this myself as a way around the pausing of the syncing off playlists when you're not active on your iPhone. A feauture which has literally not a single advantage, and how are you idle when you are actively syncing playlists..

Spotify offer me a job, really 🙂 😛