Is something not clear with the discount when adding two products belonging to the same discount?

Question

1C-Bitrix

In general, the size of the discount in 1s Bitrix costs 35%, the conditions for applying the discount: Product field Equals Or Product field Equals Or ....
If we select one product from these conditions, everything adequately shows 35%, but if a second product is added at a discount, then the size of the discount becomes 44.75%, did a discount of 20%, it becomes 32%... As long as the discounted product alone shows everything correctly... What could be the problem? I deactivated all other discounts in general, nothing changes. With goods from other discount categories, everything is also fine, when they are added to the cart together. Tell me which way to dig?