I've had a number of occasions now where guests book for one person and then have more people staying and Airbnb does nothing to support the host.
Today I had a guest due to check in, they said in messages that the booking was for a couple, husband and wife, but only booked the property for one person. Oh and dog too even though I have a not pet policy. I forwarded the rate adjustment and they refused it. I asked Airbnb support to help.
Instead of helping me they allowed the guest to cancel on the day of check in with a full refund, I've lost income and had the property blocked out because of this booking.
This happens so often that people lie to cheat the book rate and Airbnb does nothing to support the host.