Restore folder is empty

Hello All,
I have a problem restoring deleted emails.
After submitting a restore job for an account I get this message:

- stats -
Restored Items: 20
Skipped Items: 0
Unrestored Items: 0
Operation requested by: xxxx@tebibyte.it

ZeXtras Version: 1.8.11

So I expect to find some messages in the undelete new folder.
Unfortunately the folder is empty.

Real time scanner is enabled and I get periodical reports on smart/full scans being successfully executed.
Thanks for your support

Alberto