Album art not showing on saved tracks

[Fartbrain]

So about a month or two ago the album art stopped working on any tracks I saved (pressed the little plus next to the title and it turns into a tick, saves them for offline playback etc). So now all of my saved tunes have a blank/generic grey album cover of the blank record.

What i have tried:

Uninstalled Spotify following this guide: https://community.spotify.com/t5/Android/COMPLETE-GUIDE-How-to-fix-most-Android-issues/td-p/914257

Uninstalled, checked there was no local content, removed from 'offline devices' in account settings (did this about 5 times)

Reinstalled, same result

I actually broke my phone and got a new one and the issue carried over to the new one

Pixel XL, Android 8.0.0

I have been a premium subscriber for a while, even now paying for a family membership for my family, so I'm kinda pissed off at paying monthly for a buggy app.

How do I rectify this?