There seems to be an issue with jqGrid when utilizing the Virtual Scrolling feature. The issues is on initial load of the grid it only lets you scroll to the rowNum: 20 amount. But if you invoke/trigger an action on the grid like sort on column after that action you can then scroll the grid past rowNum: 20 you can scroll it any where in the result list of the grid.

Here are my two grids that I have configured, and am using the latest 3.8.1 version:

jQuery(“#groupObjectItemsOutGrid”).jqGrid({