Hi,
I’ve actually solved this one myself.
It was very obscure and I found it almost by mistake.
Because I am working across multiple audio levels and the sound I was using was based in a Blueprint, it confused me.
I had to change my level streaming method from 'Blueprint to ‘always loaded’
Go figure, lol
Seems like a school boy thing to do once you know but thought I’d post back in case anyone else comes up against it.
Thanks NJ 