At what stage is the data from the provider transferred (assigned) to the elements of the basket?

Question

1C-Bitrix

The essence of the problem: when the same product with different prices is added to the cart (the price type is written to the property), and then the prices for the same products are calculated according to the last of them.
example:

• added a product at one price: https://yadi.sk/i/Oex2REbHUbrzIA
  
• added a second same product at a different price (the price of the first product was recalculated): https://yadi.sk/i/xqkutz2odEh0WA
  

The problem seems to be in the provider, it creates elements by product id, i.e. for entries in the cart with the same product id, it creates one item. and substitutes the received data for all entries in the cart with the corresponding product id. maybe someone knows the place in the code (Bitrix core) where the data from the provider is substituted into the basket?