I have come to the conclusion that the player can't hit my license server.
For reasons unknown...
I can play back other DRM content on a different license server, but as soon as I switch back to my license server I get no request coming through. I have verified this so far by loading my drm keys into two different servers, works on one not the other.
I haven't been able to spot the difference between the two servers so if anyone knows how to debug the http info on the license request to see what error is being thrown that would be great.
Tomorrow I will load my content keys into the other server to see if it plays back using that server as final proof it's a license server issue.