Magento 2 order missing while place with online payment gateway.

Magento 2 order missing while place with online payment gateway. 

I am getting an issue very long time with online payment gateway. Some orders are not created in backend but payment was successful in payment gateway portal and user is also getting mail of order confirmation with order id. But order is missing in Magento2.3.x-p1 backend. 

Magento 2 sales dashboard screenshot.