My property is showing that it has no availability on our site from 8 Sept to 30 Sept.

This is the partner forum and not the help desk.  But you can do this yourself. 

To check your setup Open Rates & Availability, Calendar - use List view.  Dates should be in Green if available.  If not look at if Open/Closed, rooms available, Rates set.  You can use a Bulk edit to update if needed.