@Constantinos27
Are you searching using the map view or the list view? If it's the map view, the update that @Anonymous mentioned doesn't actually show all the available listings that match your criteria. I have had to sometimes zoom in directly over my house before it will appear on the map. It's ridiculous.
Also, if you are using the 'any weekend', 'any week', 'any month' etc. filters to search, it won't show you the first available dates, but random ones that can be months and months into the future. So, it could be that you think a listing isn't available in the timeframe that you had in mind, when it actually is.
The whole thing is a bit of a mess.