Old backup chains not deleting per backup strategy

I'm running Backup & Recovery 17 Free using a backup strategy of "Chain of full and incremental backups"; Number of increments until next full = 6; Use backup retention (checked); keep backup chains = "By number of chains"; Number of backup chains to keep = 2.

I'm only 8 weeks into using this product and twice my backup has failed with the destination drive full. The cause each time due to old backup chains not automatically deleting. The best I can tell is the product has never deleted an older backup chain. Does this really work or do I need to resort to an external solution?

Although this is quite an old topic, I just ran into this (well, actually since quite a while), and wanted to show that this is not just a single-user issue. Can Paragon please comment on this?

Paragon will not comment here... from an email from support I know the forum is no longer supported