Solve a Prestashop issue: Reduction group applied twice to orders from backoffice

I have an issue on a prestashop store backend I created a report in Prestashop Forge Web with the explanation of issue and a screenshot. This is the url: [login to view URL] The issue is: In some foreign (of other countries) customers, if you edit an order made from the backoffice, adding a new product, this new product is added with duplicate discount. I attach a screenshot with a sample order that you see in the backoffice with ID 10186. The customer is 13373. One of the items is added via Web (frontend) correctly, with the corresponding discount of the client group. Then, when I edit the order from backoffice, and I add a new product, it is added with a duplicate discount. I attach data of backend, please, only put the final price bid if you can solve the issue. Thanks.