Metrics being collected but charts dont apprear

Hyperic HQ Server and Agent 4.6.6

I am having an issue where metrics for my JVM servers do appear to be getting collected by Hyperic but the charts say otherwise.

Here you can see that metrics such as Heap Memory Used/Free are displaying on one screen:

But here you can see that the charts for these servers say that Nno metric data is available:

I'm out of ideas. Does anyone know what might be happening here?