Capacity Planning Thresholds and alerting

I am trying to test whether disk volume alerts will work for new Linux nodes we added through net-snmp.

I selected Settings > Manage Nodes thenselected the server and a volume ( /)and clicked Edit Properties.

That brought me to this screen:

I checked "Override Orion Capacity Thresholds" and then changed the Warning and Critical thresholds to be below current usage.  I tested with "Use Average values" and "Use Peak values" but did not receive any alerts.  Though I did see Warning (in yellow) and Critical (in red) in the GUI under Volume Capacity Forecast for this node.

Should I be receiving alerts?  And if yes, what other settings should I check?

Thanks