My listing "Mafiris Homely Loft Apartment" has notes on 20 August through to 31 August on the listing calendar, but dates are available. The note says "Blocked dates". I have tried to delete the note without success.
I've just been onto the listing you mention and I see a 404 error from Airbnb so that's not good. You're going to have to contact customer service to find out why this listing is no longer available on Airbnb.
Have you had any recent bad reviews or problems with a guest that you can think of? Are all the legal requirements entered for this listing? There can be a few causes so impossible to advice accurately but let us know what the problem was for others who may find themselves in your situation