John,
The OnPlus Agent itself is monitored from the portal, all other monitors are run from the OnPlus Agent. The portal monitoring can't distinguish between the OnPlus Agent being turned off, rebooted, or disconnected, and some other connectivity issue (local switch, router), bad WAN connection, etc. So the problem is reported as an event which is labelled "OnPlus: Connection Status" when adding a notification rule.
To avoid false alarms, the event is raise as a Notice if the connection loss is expected (for example if the OnPlus Agent is expected to reboot due to a software update or a reboot command from the portal). The event is raised as a warning if the connection loss was unexpected. The default notification rule is set to alert on unexpected connection loss and not on expected connection loss.
So in this case if you look at the event history for the OnPlus Agent you should see the events listed. If you want notification of the expected connection loss, you can add a specific notification rule for that.
As an experiment, you can unplug the OnPlus Agent and you should see a warning notification within a minute or two.
Andy
