In this case is it normal I can see one xbin file with modified date 27/09 ?
Seems there’s only one and all others are 10/10 or 11/10 (24h as you said).
Files in this folder should be deleted automatically after 24 hours or upon Server restart. There could be some scenarios when Server fails to delete expired file records (mostly involving file access failures) and that should be visible as Could not delete result... message in Server log.
Server restart should remove all such records and would act like a purge.