Local files won't play on iPhone app

[pairadice]

Hi,

I've read several other threads about this but no suggestions have worked for me yet. I have some local files on Spotify on my laptop, which I've then added to a new playlist, made available offline, with my iPhone and laptop on the same wifi, and tried to play them on the phone. The new playlist does show up on my phone but the songs are faded out and it gives me the "Song Not Synced" error. How do I get them to sync?