It is possible that an electronic payment (for example iDEAL) is not completely successful. You will then receive a notification from the system as a web shop owner. Most likely the following situation has occurred:
The customer makes an order with you and at the moment he / she chooses an electronic payment method he / she ends up on the page of the bank. On the page of the bank the customer can make the payment. When the customer interrupts the process there, for example, closing the browser, the order is not completed or if one has paid but does not press 'go back to the webshop' there is no completed order. After all, the system can not check what happens on the bank's website site. If the customer does not return to your website, you will receive the order within 2 hours after the order has been placed. As a result, you will not miss any orders at all.