The DLQ Depth is not shown under the Queue Manager dashboard, but it is shown under the "Queues tab".
WebSphere MQ is case-sensitive. The queue set as the dead letter queue in WebSphere MQ did not match the queue name when capitalization was considered:
"DL.Queue" vs "DL.QUEUE"
Set the name of the dead letter queue in WebSphere MQ so that it is consistent with the queue name.
You can modify the dead letter queue name in two ways:
1). Issue the following command:
alter qmgr deadq <DL_queue_name>
2). Change the name directly in the MQ explorer
The issue was detected within the properties of the MQQueueManager topology object instance associated with the Queue Manager. The value in the "deadLetterQueue" property had different letters capitalized than the MQLocalQueue observation value for the queue:
foglight-5:MQLocalQueue:de579bdf-a6cd-49c9-8434-d72af6d97d82:3 datasource=foglight-5:foglight-5 (DL.Queue)
You can gather the properties of the MQQueueManager object instance with the following steps:
1). Navigate to the Script Editor (Administration | Tooling | Script Editor).
2). Select "MQQueueManager" in the Query drop down list and click the "List Instances" button.
3). Click on the link associated with the Queue Manager.
4). Copy all of the text from the Object Properties section and paste it into a text document.