Discounting Order Tag prices

Discounts are not applied to order tag prices. I will explain this by example.
Product has been setup Schnitzel. The product can have Gold, Platinum or Staff discount. Schnitzel can be made from Chicken or Pork meat. Upon selection of the product the meat has to be selected using order tags. Chicken adds $1 and pork $2 to the Schnitzel price.
Assuming the customer is Gold level then he gets the discount from Schnitzel price, but it is not applied to the Order tag price.
To clarify here is how it looks like.
Schnitzel cost $5
Chicken will add $1 to the price, total $6.
Gold level discount is 20%. The customer will end up (1 - 0.2) * 5 + 1 = 5,
Whereas it should end up (1 - 0.2) * (5 + 1) = 4.80

I am not able to locate where the calculation takes place.
I am using SambaCard implementation over version 5.
Please, can I receive guidance how to correct the calculation.

I got this thing figured out already.

Please share your sollution for issues for future readers on forum.