As per current custom event alerts the threshold is set to raise an alert if availability falls below 100% for 1 minute out 5 minutes period. However, in the case the queue is down the current scenario no data is treated with the problem closed. Creating a scenario where the original queue down problem gets closed after every 5 minutes and reopens when again when queue plugin tries to look up data in a couple of hours. When such auto-closing problems are linked with ServiceNow integration, they end up creating multiple tickets on the user end.
In short, if there is no data coming for IBM MQ, the problem raised for the first time should remain open and duplicates should not be raised. And when the data starts coming the problem is resolved.