Your piechart is based on yoru current found set and sort order. When you perform a find, you will pull up different records and your chart will reflect the data in your new found set. And performing a find produces an unsorted found set so you then have to sort your records to regroup them as needed for your pie chart.
In IWP, presumably, you need to make sure that you also have the correct found set and sort order there. If you are relying on a script trigger to produce the correct found set and/or sort order, they can't be directly "tripped" by a user interacting with a web browser so that may explain the difference.
I can't tell from your post what a value list has to do with this piechart. Perhaps each 'wedge' of the chart represents a different value in your value list?
I figured out the sorted part late last night, I have to test placing the button to transfer me to the "chart layout" which have embedded sort step in it, and then another one when You go back to original layout, for the unsort part.