The alert suppression does not work as you would logically expect it to, and so this alert is not firing.
It looks like your objective is to not have the alert fire if CriticalNetworkComponent is equal to Yes. Remove this from the suppression tab, an add it to your trigger condition, reversing the logic, i.e. CriticalNetworkComponent is not equal to Yes
The event log notification you are receiving will be the internal "Node down" warning (EventType 1) and would be red, rather than "Alert Triggered" warning (EventType 5000) in yellow.
hope this helps