Billing address should not send a 0 to PayPal Standard
under review
Ben Meredith
under review
Our team will have a look at this. In the meantime the workaround is to either not collect the billing info, or to have the donor delete the 0 in the PayPal interface before submitting the donation.
Issues like this that are not preventing donations or have a simple workaround are generally prioritized at the end of an 8 week development cycle, and then tested and released. That means it can be up to 10 weeks for issues like this to be resolved.