Why does the awstats interface in cPanel not show an entry for my addon domain?
The traffic statistics for Addon domain are included with the associated subdomain that is assigned to it when it was created. The awstats feature pulls traffic information from the domain logs created by the Apache service. The Apache service is designed to label these logs by the name of the primary domain in the vhost, which is the subdomain that was created.
To view your Addon domains traffic you will need to view the subdomain logs instead. The Addon domain will be listed next to it under the column Linked Domains. If you do not see the subdomain present, you will need to ensure that this has been enabled for the awstats feature.