Linux LG resource stats

We have introduced  a Linux Load Generator server to our overall pool of hosts (the others are all Windows).

The Linux LG server is working fine when we test. However, 

when we look at the snap shot of the test during execution, we are only getting stats for the Windows Controller server and nothing for Unix resources either with the LG set up as a standard resource for monitoring.

I would have thought that we should see both the controller and the LG in the bottom left graph. attached.

Can anyone please explain why there are no resource (memory, cpu etc) stats for the Linux LG server? 

 

Missing Linix data.PNG