When the data is initially grouped and later grouping is collapsed, the group does not expand on click again.
The class rgExpand does not change to rgCollapse class.

It works with Telerik.Web.UI.dll version 2014.2.618.40 (release 1/14/2016?)

However, when we upgraded to 2016.2.504.40 (release 5/9/2016?), it is stuck in "Collapse" mode. Cannot expand again in when clicked on the arrow.