Someone mind offering a brief explanation of associated actions. Thank you.
The Acknowledged box is a people-tracking flag, not a system control. Checking it just says, "a human has looked at this one." It doesn't resolve the condition, doesn't stop it from firing again, and doesn't cancel the Send Email action the next time the threshold trips.
Where it earns its keep is filtering. Hit the filter icon on that column and set it to unacknowledged, and the log turns into a triage queue instead of a wall. In your screenshot you've got nine identical "Blocking SQL: Duration Threshold Max" rows, ack the ones you've already looked at and whatever's left is new since you last checked. Pair it with the Assigned User dropdown on the right so there's no ambiguity about who owns follow-up.