The expired backup sets on the locally managed Backup Exec server are not getting deleted by the DLM.
A hotfix is now available for this issue in the current version(s) of the product(s) mentioned in this article. Refer to the Hotfix link under Related Documents at the end of this article to obtain the hotfix needed to resolve the issue.
Backup Exec 2012 Rev 1798 Service Pack 3 (TECH205351).
Central administration server is BE 2012 SP1
Managed Backup Exec server is BE 2012 SP1 (Locally managed Backup Exec server)