Describe the bug

This issue occurs only with a different currency than the default one.
A customer Group has a discount category for example 50% for the Art category

In the BO > Orders > Order page > when we Update a product(which is in the category discount) => the product's price is NOK.
If we generate the invoice => total incorrect

Steps to Reproduce

Steps to reproduce the behavior:

1. Go to BO > International > Localization page
2. Import the United States pack
3. Go to the currencies page
4. Edit the $ currency with exchange = 10 (only to visualize the issue)
5. Go shop Parameters > Customer Settings > Groups Tab
6. Edit the customer Group, Add a discount 50% for the Art category
   
7. Go to FO > Art category > Select $ currency > Add the product demo_18to the cart
8. Continue checkout
9. Go to BO > Orders > Open last Order created
   
10. EDit the quantity of the product ordered ( from 1 to 2 form example)
11. Save
12. See error => the product's total is NOK
    
13. Change the status of the Order to Payment accepted
14. Download the invoice
15. See the error
    

1770finalbuild => NOK: https://drive.google.com/file/d/1IYCHdcMkUTZ_G_1K7QsWMywcziDSSc-x/view?usp=sharing

PS:1769 => ok: https://drive.google.com/file/d/1dojva4t7oLJDFw1ZLxiV7RbfzmRCIZUy/view?usp=sharing

Additional information

• PrestaShop version: 1770finalbuild1
• PHP version: 7.2