Linking Sales Orders created from Return Authorisations

Hi,
This is related to Warranty and Repairs

From a warranty registration, we can create a case and then Return Authorisation and then from that we can create a sales order. However sales orders created from Return Authorisation are not linked to each other. Meaning when I look at Sales Order > related records, the return authorisaion is not shown.

Interesting fact is that when I click on Create Sales Order, the Return Authorisation number is shown on the field "Created From" before saving the sales order, but it disappears after saving it.

How do I link the sales orders that are created from return authorisations, to those return authorisations? Ideally they should appear under 'Created From' on those sales orders.