Apple Watch - No Music In Apple Music

Apple Watch Series 6 paired to an iPhone 11. Was working fine until last year, not noticed the exact time this issue began:

I'm trying to sync a Playlist to my Apple Watch using the app on my iPhone, to keep the playlist on my Apple Watch so I can go for a run without my phone and listen to music. However, it just doesn't complete the sync.

The Watch is connected to my Apple ID, shows in my Apple account and syncs everything else. However, when I go into the Music app on the Watch itself, I can access the Home tab but cannot view any Artists, Albums, Playlists or Songs. Does anybody have any tips as to how to solve this? I've reset my Watch to try and resolve this, and deleted the Apple Music app from my iPhone.

Thank you in advance!