Songs not syncing

[csna]

Plan

Premium

Country

Australia

Device

iPhone SE

Operating System

Windows 10 Pro

My Question or Issue

When saving songs on my iPhone SE (On the latest iOS) songs do not sync accross at all. I have to log onto my PC at home and manually find all the songs I've saved on my phone and add them. However when adding on my PC the songs sync across without issue.

I have tried the following

- Reinstalling on both PC/Phone

- Logging in and out of my spotify account 

- Offline mode and then back on

This is getting quite frustrating as I am adding songs on my phone very regularly and I do not want to have to manually add them everytime I get home.