@Jaqi0 Are you sure they were Reservation Inquiries? Or was the guest asking questions in a Reservation Request. Guests often do that when they really just want to ask questions.
If they sent you a reservation request, the dates are blocked until you Accept or Decline the request. Go to Your Reservations to verify what the guest really sent you. If it was a Reservation Request, that would explain why you don't have a Pre-Approval option as it is not available for Reservation Requests.
To make matters even more confusing, I've noticed that emails I've received from Airbnb about a Reservation Request says to respond to the guest's Inquiry. By checking Your Reservations, you will see what it really is.
Hope this helps!