It may look like that, but no, this is not possible. 🕵🏻 Okay. Then what exactly is going on? Let's raise the curtains on this.
A second return request can be created for the same order. Regardless of this, products that are already included a previous return will not be eligible to select in the second or latest return.
Please check the quantities of the items in the original order on Shopify and compare these with the quantities of items in the different return requests.