NOTE: If your VWO account is enabled with Data360, you will be able to use Metrics instead of Goals for tracking standard and custom events on your website. However, if you are encountering a similar scenario, the explanation provided in this article will still stand applicable.
VWO tracks the 'visit to a page' goal as soon as a visitor arrives on the page, but the 'revenue conversion' goal is triggered only when the Document Object Model (DOM) is ready. If a visitor leaves the page before the DOM is ready, VWO records only the 'visit to a page' goal. This explains why the numbers of conversions recorded for the two goals may not be the same.