I have some local files in iTunes on my Mac in Playlists in Spotify and they first weren't appearing on my iPhone, but then I enabled showing songs which were unplayable, so now they appear as greyed out on my iPhone, and I can't play or download them. (When I hit the playlist download button it just says 'waiting to download'). When I attempt to use airplay to play the songs on my computer to my iphone an error message says you must download these songs before you can play them and gives a set of instructions which don't work. Please Help!
All devices’ software is up-to-date. If you don't know, check with your devices' manufacturers for how to update the version software. If possible, try switching between different networks and see if that helps.
Try using mobile hotspot to connect the devices to the same network before downloading the songs. If there's too many local files, try with just a few with a test playlist.