It's not as simple as yes or no. Have you looked Airbnb Help Centre to look at what they say about guest cancellations?
Did you ask the guest why they didn't stay?
Any refund given should be in line with your cancellation policy.
However if the guest can demonstrate your listing is not as described, key services or facilities are not working, or say there is an insect or rodent infestation then if they notify Airbnb within 24 hurs and and can provide evidence of this, then they can ask for a full refund.