Coupon code for single item in Cart breaks checkout

Hey Guys,
I have a client who just set up their store and all was fine until we tried checking out with one of the coupon codes they created. So the coupon code is nothing fancy just a string of text.

The settings in the backend for the code are as follows:
Coupon Code - STORIES75, I changed this to TESTCOUPON and and the results were the same
Discount Amount - 75%, I also tried with specifying 75% of the product's price here
How should the discount amount be applied? - Apply to each applicable item once per cart
Can this coupon be combined with other coupons? - NO (UNCHECKED)
Max Uses - BLANK
Applies To - Product
Product - We selected a product here
Start Date - July 7, 2016
Does coupon have an end date? - NO (UNCHECKED)

Now What happens when I pressed "Checkout" on my cart with the selected product, some others, and that coupon code I filled in my Canadian address,I tried this with an American one as well just to double check, and go through the review process. Once done that I click the "Submit Order" button and after a moment I am redirected back to the page I am on but this time I get an error saying:

OOPS! AN ERROR OCCURRED WHILE PROCESSING YOUR PAYMENT.

10413 - The totals of the cart item amounts do not match order amounts.

doing a search for that error returns information from PayPal so I am assuming the issue is with the plugin because PayPal is basing the information off of what the plugin gives them. Next I did a modification of the coupon code and found that if I changed how the coupon code was applied in the backend the checkout process works perfectly. sending me to PayPal's website. See here: http://prntscr.com/bt3g3j

So what I am wondering is why does this break when setting the discount to applicable for each item once per cart?

Extra Notes:
I also noticed that the Coupon Discounts section is slightly weird when reviewing the order. I am getting this:

Product Total          $15.00
Coupon Discounts     --$11.25
STORIES75            --$11.25
Shipping                $4.00
Order Total             $7.75

Thanks in advance,