The reason is usually pretty simple - because they are undefined. Whenever QueueMetrics runs a report on a queue, it loads the "agent level" information from that very queue definition that is being run - this means that if you use the same queue multiple times, e.g. once by itself, once as a member of an aggregate queue, you'll have to set the agent priority for all cases.

In order to assign agents to a queue, you follow the following procedure:

• Go to the queue editor and select the queue you're reporting upon (from the main page, click on "Edit queue")
• Click on the agents icon for the queue you intend to work on (that's the middle icon on the right with little people showing) - you should be driven to a page with "Main", "Wrap" and "Spill" columns
• Click who is who for each level - "Main" is the first line level, "Wrap" is a backup for Main, and "Spill" is the backup for Wrap.

Of course, in order for this to produce meaningful results, you should set up penalities accordingly in the queue definition for Asterisk.