Hi,
You need to check the entries in the table hikashop_order_product
Check if you find entries there for an order with the problem.
If you don't, it means that the entries are missing from the database. So the problem is that not all the data was migrated properly for that table. You'll have to get the data from the backup and add it there manually.
If you do, then it means that the data of the products is not correct in that table. For example, the order_product_quantity is 0.
Based on what is not ok compared to the products of order which are ok, you'll be able to find what is the problem with the data. Then, based on that, the action to take will be different.