Hello! 

The support site got a fancy new Optimizely design but the feature "THE "GET A NEW PASSWORD" OPTION WILL NOT WORK" was ported as well, so here I am in the forum making a bug report :D

Description
The SpendAmountGetItemDiscount (Spend for Discounted Selection) only allows 1 instance of this promotion type to be applied on the order, even if it only targets 1 of the line items and there are multiple others. The other line items cannot recieve rewards from other  SpendAmountGetItemDiscount. This even if you run with PromotionExclusionLevel = entry. I've tried this on 13.21, 13.25 and 13.30.

How to reproduce

1. Add Item A and Item B to cart
2. Log in to epi admin, Commerce->Marketing and create a new promotion under a valid and active Campaign.
   1. Promotion type should be "Spend for Discounted Selection". 
   2. Spend at least 1 in all currencies
   3. Find Item A and drag it into the "Get..." content area
   4. Add a percentage off, say 10
   5. Make sure it is active.
3. Repeat step two to create a new promotion. The only difference is the third step, where you instead drag in Item B. So now you have 1 promotion for each item.
4. Run promotions on the cart with ExclusionLevel = ExclusionLevel.Unit. Make sure you get rewards on both items, you should see a respective % decrease on both items
5. Go back to epi admin, Commerce->Marketing and click on the discount order button top right
6. On your second promotion, that affects Item B, which should be further down the list than the other one, click the plus to add "Cannot be combined with...".
7. Select All and hit OK. 
8. Press save top right.
9. Go back to your cart and run the promotion engine with the same setting.

Expected result

Both items get a discount. Even though the promotion for Item B excludes the promotion for Item A, they are not affecting any overlapping items.

Actual result

Only Item A gets a discount.

Workaround

None if you want to utilize everything SpendAmountGetItemDiscount can offer, but this bug does not exist on BuyQuantityGetItemDiscount, so that can in some cases be used instead.