I"m having the same issue. When I try to add PP as my payment preference instead of my bank account. I get an error message that says" the zipcode entered is not valid", when it never asked me for a zip code, didn't enter one! I called Airbnb support and they have no idea and asked if I'm using the current app. Well, as far as I know I am. If it told me to update at any time, I've done it. Then they asked for a screen shot of the error message. When I try to do that it says "not allowed due to security"...This is very frustrating as I need that payment method changed asap.