TableView scrolling bug

I have a TableView with a lot of data in the table (10,000 rows plus). And I have scrolled all the way to the bottom of the table. At this point the vertical scrollbar slider button is quite small.

I now clear the items list behind the TableView, set the scroll index to 0, and add 100 items. The TableView immediately scrolls to the bottom of the 100 new items. And the vertical scrollbar slider button is still very small (i.e. it hasn't updated to reflect that I now only have 100 items).