Hey @atcasestoreindia,
Thanks for sending those. I was able to see all of the notes for order 10814. Here’s what I spotted.

The order status is set to processing by the payment gateway after the transaction is successful. Then the status was manually updated to “pending payment.” This is an “unpaid” order status. It doesn’t remove the actual payment but it does indicate in the system that this order hasn’t been paid for.
That’s important because there is a system that automatically cancels unpaid orders. Once this order is set to “pending payment” that starts a timer. Once that timer runs out, the order is automatically canceled.
You can change the length of time before orders are automatically canceled or disable it completely. To do that, go to WooCommerce > Settings > Products > Inventory. The “Hold stock (minutes)” field sets the time. You can enter a longer number here to give more time before orders are canceled. You can also remove the value so that it’s empty. That will disable this feature.

Try making some changes here and see if that helps. Also, it’s typically best not to change the order status to pending payment after it’s moved to processing.
You can learn more about WooCommerce order statuses here:
https://woocommerce.com/document/managing-orders/#order-statuses
I hope that helps you get this cleared up.