In my Drupal Shop I have some products with different edits. For example the Colour 300ml with option yellow, green and brown. And the Colour 500ml with the option yellow, green and brown. I also have different pricing volumes (ubercart pricing volumes) -> At a quantity of min. 14 pieces, the product is 1$ cheeper etc.

My problem is that the cart doesn't count the items together which are from the same product. So I buy for example Colour 300ml - yellow - 10 pieces In the cart it tells me: buy 4 more of Colour 300ml for a discount. So I buy additionally 3 of Colour 300ml brown and 1 of 300ml yellow. But in the cart they are seperate. So now it tells me buy 2 more of Colour 300ml for a discount and buy 11 more of Colour 300ml for a discount. One for each colour.

Does anyone know what to do? I've tried to edit the code, but it just counts the colours togehter but is not adding the discount. Thanks
(Drupal Version 7.50, and ubercart shop module)