@Henley0 same thing here, I also got 1*
A young couple, new account, no reviews, arrived in a camping wagon. Seemed friendly, but were late 2 hours, leaving me waiting. Stayed till the end of the reservation (3 nights) and checked out. Didn't hear from them until 2 days later when they messaged me, showed pictures of red dots on their legs and some fluff on the sheet said they were bitten the first night, slept the other 2 nights in their camper but used my bathroom only and asked for a refund. I didn't reply the same day and the next day they wrote a review and complained to Airbnb about bugs.
I immediately called the exterminator company, they came, inspected, didn't find bugs but treated the apartment preventively, in case this couple infested the apartment themselves. I submitted the certificate to Airbnb the same day.
They were not refunded, my listing wasn't suspended, I got a bad review and gave them one too.
I am pretty sure there is some website or Facebook group with instructions and tricks on how to extort the refund and stay for free in Airbnbs because the MO is always very similar.