I do not know if this is a bug or an intended feature, but if it is the latter it renders all food-focused businesses in the newest pack completely unviable.
In attempting to create a bakery today...
Ideas
I have the same problem. Put out batches of candy in Sweet Treats display item and they buy the entire stack but only pay for 1. I do not use any mods or CC. I too am now using the work around by only placing single items in display.