@Nash-Cottages-LLC0 Here's the deal as it appears to guests: https://www.airbnb.com/help/article/245/how-do-i-pay-for-my-longterm-reservation
Airbnb considers any booking over 28 days to be long-term. They do charge a service fee, based on the entire booked period and split up into the monthly payments. The entire service fee should be displayed to the guest in their request just before the grand total for the entire 4-month booking.
If Airbnb is unable to collect payment after the first month has elapsed, the only thing they're able to do is cancel the reservation. If the guest is protected under your jurisdiction's tenancy laws, you might be unable to legally remove them from the property without a court-ordered eviction.