2019 Datacenter in AWS as Terminal Server

Hi All,

We are running a TS in AWS, its a 2019 Data Centre License, and we have 15 2019 per device CALS for users to access the TS.

The licenses are showing fine - and users can connect and log into the server fine - however the CAL's aren't allocating and because of this users are kicked every 60min. The License manager seems to complain that the host server is 2016 when it is absolutely 2019? WE aren't using a broker or gateway or anything, just a single instance. 

Any ideas?