Gift removed after adding new line item

Description

Precondition:

• Gift promotion "Buy $100 get a Women's Beauty Package"
• Women's Beauty Package: In stock = 2

Steps to reproduce:

1. Go to Quicksilver.
2. Add 5 Puma Red sneakers to a cart.
3. The order subtotal is $210.
4. 2 gifts are added to the cart.
5. Place the order successfully.
6. Go to Commerce Manager.
7. Open the above order.
8. Add 1 tank maxi dress to the order.

Expected:
Gifts are still in the cart
Actual:
Gifts are removed.