Apple Music: Song Not Available In Your Country. But It’s In The iTunes Store

Apologies if this has been asked and answered, the search function here is woeful.

My account is in Australia, I recently purchased three albums from the iTunes Store on my phone (no VPN or other geoblocker).

When I went to play the songs in the Music App the Albums disappeared from my library and the songs were “Not Available In Your Country”… if I could buy it in the Australian iTunes Store, why is it not in my Music App and how do I fix this?