Local Files will not Sync from Mac to iPhone

[buttertruffle1]

I'm currently using a Macbook Pro with the MacOS Sierra version 10.12.2 and the new iPhone X. Before the iPhone X, my Spotify had suddenly stopped transferring local files from my Macbook Pro to my phone even though I connected both to the same wi-fi and turned on downloads. Now that I changed to the iPhone X, it's still not working. On my phone, it will still show the correct number of songs in each playlist, but when I open the playlist, none of the songs from my local files are there. There's a grey arrow next to the playlist, but still, when I open the playlist, it's empty (the name of the unavailable songs aren't even there). Please help! I've tried reinstalling the application on both my phone and my laptop, and used a different source of wi-fi and nothing seems to be working. It used to work, and now that it stopped, I'm thinking of using Apple Music, although I really like Spotify. If anyone has any suggestions, please let me know.