I don’t know if you eventually sorted this issue. Today, June 2022, I am now encountering this problem. I have learnt it’s my bank refusing to work with the Air BnB card registration method. To register a new payment card Air BnB requests a small deduction from your bank account to, I guess, verify the account is valid. However, my bank isn’t allowing this procedure because of the sheer quantity of fraudsters employing this procedure, eventually making larger deductions. This is the long version short. My own and one or two other banks have been burned this way since Air BnB is popular with fraudsters and between Air BnB and many financial providers there has been no collaboration to get around this problem. So speak to your bank and see if this is the case.