Acronis stops the job when the limit of copy is reached

Such a symptom I found on different servers in different domains , and under different conditions , so it's only in Acronis .
So:
-
We have a server 2008 and installed Acronis Backup & Recovery 11.5.
Create the full-backup job on a daily backup to another drive, and keep amount of 14 copies of this backup.
When Acronis fulfilled all 14 backups ( ie the last 2 weeks ), Acronis stops further execution, and if forced to right-click on the task and want to run it - we only see the " Replication ", and " Run" options not availadble.
If somehow change the task, for example, to change the time by 1 minute, it will once again be performed regularly, and and I can run the task manually by right-clicking, but after a while (and it will not necessarily 14 days) again to stop his execution.
In addition, Acronis log`s are absolutely clean.

How to fix this nightmare?
Thanks for assistance.