Hi Janine -
The bugs in the calendar system are my one big issue with Airbnb. I managed, eventually, to have my Superhost status restored but it wasn't exactly easy. Be patient yet determined to resolve the issue both in your and Airbnb interests!!! I actually have a disclaimer now on my front page of the listing telling browsers that I cannot accept bookings more than 6 months in advance. This is precisely because of the reason you have experienced!
I suspect if any Airbnb host looks ahead that far in their calendar that they will see booking as available. For that matter, any potential guest will have the same experiece...
Persevere, Janine and it will be resolved.
Happy Airbnb hosting (and all that jazz!)
Fi