SSR 2013 - Hangs when viewing Backup History

In SSR 2013, when I click on Advanced -> Backup History, it starts listing the backup history, which contains hundreds or thousands of entries.  It takes a few minutes while it adds every item to the list, from oldest to newest.  When it looks like it is done and I can see the newest items, it clears the list and starts over.  It stays stuck in that loop until I kill it.  How can I purge the Backup History, either clear it completely, or preferably, remove the old items like more than 3 months old?