Me and my pregnant wife arrived at 1 in the morning, followed the instructions but the apartment was still in use by other guests.
Waited for 1h until they offered us another appartment. Drove to the other Appartement, turns out, this one was also booked.
They excused the 2 mistakes and told us at 4am we had to book somewhere else or go to a hotel.
Worst experience I had with Airbnb this far. I hope you got this in check now.