We have an issue with orders not coming through our store once the customer has processed the payment via our paygate. There has been a couple of instances where a customer would pay and paygate would confirm transaction but the customer could not received order confirmation. We also do not get said customer’s order on our end.
As per your concern regarding orders not coming through your store after the customer has processed the payment via our paygate. It looks to be an issue from the payment gateway end you need to contact with their support team.
Moreover, I would definitely suggest you to check you payment gateways settings on the shopify admin dashboard to verify if it is correctly set up or not ( Shopify Admin> Settings> Payment Providers section ). You can also make the use of Shopify guide to make sure that your payment gateway is set up accordingly.
Happy to help! As @Recurpay has suggested it does appear to be an issue with the payment gateway itself. However, it could also be an issue specifically with how the customer is checking out. Is this across all orders or just a few? Do any come in at all?