I had a similar problem. My problem was because I was putting a bank account in the name of my partner, i.e. different to my AirBnB account which is in my own name. AirBnB obviously don't seem to accept this... though the error message didn't specify that this was the problem. When I changed to be paid into my own bank account the payment method was accepted. Of course yours may be a different problem. Hope this helps.