Saved and downloaded songs not syncing from PC to iPhone 4

[slgla]

Okay, so I have Spotify Premium and have around 800 saved songs added to 'your music - 'songs' that are all downloaded so I can listen to them offline. This is both on my iPhone 4 and my PC. However when I save and download a song to 'your music' on my phone, it does not save onto my PCs 'your music' tab, and vice versa...

I am a bit confused, as sometimes the songs sync fine and the song{s} in question are saved onto both my devices and are available to listen too offline on both my devices, but other times it does not work.

If someone could tell me why the songs are not being saved on both devices and tell me how to fix the issue, it would be much appreciated.

Thanks 🙂