We found that the MQMonitor IIB Agent would not reconnect to the IIB instance after MQMonitor IIB Agent was restarted.
The MQ component metrics would continue to report as expected but the "IBM Integration Node" metric folder would go gray.
It seems like this issue is occurring under certain scenarios. 

Release:
Component: APMAGT

Provided new fix for MQMonitor.jar, contact technical support to obtain the fix.