How do I point my RDS 2012 R2 server to pick up the RDS licences from a dedicated RDS Licence server

I have configured a dedicated server 2012 R2 box to be the RDS licence server for the Domain.

When I use the Review configuration option, I get 2 green tick circles which indicate to me that all is well. However, when I built a separate RDS Server 2012 R2 box, this server does not seem to be picking up a licence.

Can anyone help?