Discount amount isn't shown on success page

[vmalyk]

Pre-conditions:

1. Svea Checkout - 1.2.8
2. Magento Open Source 2.3.5-p2
3. PHP 7.3

Steps to reproduce:
2. Add product to cart and proceed to checkout
3. Update cart for getting discount by cart rules.
3. Fill all details and proceed to payment
4. Go through payment and place order
5. Order Success page

Expected Result:
In ORDER DETAILS section row with discount amount should be returned

Actual Result:
Row with discount amount not returned. Total correct (includes discount) but misleading for the user.