Something wrong with the VAT

We use this plugin for more than a year. It worked well until the update of August. Our shop is connected to webwinkelfacturen.nl, a Dutch system for invoices. If someone places an order with products without PPOM fields, the order goes through in webwinkelfacturen.nl. But if someone places an order with products with PPOM fields, the order doesn’t come through, due to a VAT error. Did something changed in the VAT settings of the plugin in the August update?