If you have multiple properties that need to connect to 1 Airbnb account/host. If you try to connect a 2nd property you will get an error since the host is already connected.
Find the property that you connected to this Airbnb account already.
Open the Airbnb channel
Add more properties to the channel
In "Affected Properties" you can add more properties here. Once added you can map the listings of these properties.