How do you think it should have been labeled, with the starches listed as sugars instead of under total carbohydrates?
Is it sweet? 18 grams of granulated sugar in a cup of milk would be pretty sweet, that's 1-1/2 TB. Modified food starch is made from bland carbs like wheat, potatoes, and tapioca, sounds like a pretty basic carbohydrate to me.
https://www.bobsredmill.com/blog/featured-articles/modified-food-starch-demystified/