Number of most recent backup file copies?

I have read this "Rollbase allows customer tenants to take ten backups per month and stores up to seven copies of the most recent backups."

from http://documentation.progress.com/output/rb/doc/#page/rb/backup-and-restore.html

Then I tried to create backup file until reach the limit (7 copies).

But when I created a 6th file, the system delete the oldest backup file.

So I got max 5 copies instead of 7.

Is there a setting that can change limit number of copies?

Or I just got bug?

P.S. I use rollbase 3.2.4.

Thanks.