Ok, i am a little further with this. I have pinned my cores for vm and dockers but it didnt solve anything. So i installed Fedora using the same cores, memory etc as my Windows 10 VM and lo and behold, i dont get any audio lag through the browser whether it is Plex or youtube!
So it would appear to be something to do with windows 10. There is definately an issue though that is my work around for now until i can try a dedicated drive for VM's