I’d love to know how this is resolved, as I am also a guest on this end just now initiating a refund from Airbnb for their fees on a canceled trip. In my case the host refunded the trip, as we could not get ahold of them and were not able to travel, due to extreme weather conditions. So now the host (thankfully) has issued a refund minus the ~$160 fee that Airbnb charged.
I can only hope they will be reasonable and refund or credit toward another trip considering we were refunded from the host and Airbnb is simply pocketing money for service that was not rendered.