Hello!
I noticed an issue using the “increment/decrement” of the products.

As you can see from the screenshot, when I land in the product cart there is no the “discount percent values” displayed in the product price.

If I increment or decrement one of the product listed in my cart, It pops a tag just near the price of the discounted products.

How to fix this bug?

You can fint it in the SNS online demo too.
http://demo.snstheme.com/presta/sns-senia/en/order