@Fran1
Hi, go to message history for guest, on lefthand side is an area 'Payment', it gives you a breakdown of: what the guest pays, what Airbnb takes and what you are left with. If the original price is different than what you set, check that you do not have smart pricing turned on, if you do, type in a minimum you will accept, or turn it off and just set a price.
Or contact AirbnbThis is a host forum not monitored by Airbnb so sometimes it is better to contact Airbnb to get a response that only they know the answer to. Best,