I have some issue with syncing the calendar with airbnb. If I close a day from hotel booking it close correctly on the sync but when I cancel the booking the calendar on airbnb remain close and locked from the external (hotel booking) calendar.
Such behavior rather depends on AirBnB settings/functionality, as the Hotel Booking removes cancelled bookings/accommodation blocks from .ics file. This means that during the next synchronization those removed events are no longer exported. You should check it our with AirBnB support team whether they check previously imported events and remove them in case they are no longer in the export link.