After you use the Suspend-Queue cmdlet to stop processing on a queue in Microsoft Exchange Server 2019 or Exchange Server 2016, more than 100 messages stuck in the submission queue but no event is raised in the Microsoft.Exchange.ManagedAvailability\Monitoring channel. In addition, the Microsoft-Exchange-ActiveMonitoring/MonitorResult channel shows the following error message:
ResultName: SubmissionQueueLengthMonitorLog Name: Microsoft-Exchange-ActiveMonitoring/MonitorResultSource: Microsoft-Exchange-ActiveMonitoringMonitor result (Name=SubmissionQueueLengthMonitor)<Error>Transition timeout should be in increasing order. TransitionId=1</Error><Exception>System.ArgumentException: Transition timeout should be in increasing order. TransitionId=1
It’s expected that there's an event in the Microsoft.Exchange.ManagedAvailability\Monitoring channel stating that the submission queue length exceeds threshold.