I'm finding errors in calculating the rules in the cart when there are products in the shopping cart that apply two or more different rules.
For the two rules, conditions have been set for discounting for manufactor and sku. That is, only if the product in the cart is a specific manufacturer and is part of a list of selected products, the rule applies, otherwise no (as per image).
How show in the cart:
Added the two products in the cart, which have a different discount rate. Magento makes discounts not on the price of the single product but on the subtotal and applies one rule at a time on the total of the two products.
total price of individual products:
p1 € 257.42
p2 € 213.35
instead, magento calculates: p1 + p2 = € 470.77 -19% = 381.32 -20% = 305.06.
the correct calculation should be:
P1 must have only 19% discount, p2 only have to discount 20%
total cart = (p1-19%) + (p2-20%) = (257.42-19%) + (213.35-20%) = 208.51 + 170.68 = € 379.19
And a total discount of: 48.9 + 42.67 = 91.57.
How can I solve this issue?