I see you're a new host and huge parts of your calendar are blocked out, so forgive the direction of my questioning:
Do you by any chance have a pending reservation request (somebody actually committed to booking) that you still need to react to?
You have Instant Book on, but if those dates have already been booked you would be able to see it in your reservations...
If that's the case, then they have precedence over pre-approval of a mere inquiry.
If that's not the case, and @Destiny3's tips don't help, here's how to
contact Airbnb