I'm working on a SharePoint site that was just upgraded from SP2010 to SP2013. Some of our pages have a DVWP with items that are grouped. The issue is that once a group is collapsed, it cannot be expanded. In SP2010, there would be a '+' icon next to the group header which would expand the group when clicked. Now in SP2013 it displays a black arrow icon (pointing down and to the right), when that is clicked nothing happens.
I'm not sure what information is needed to diagnose this problem, if you need more details please ask.
The DVWP was created in SPD2010 using the SPD interface to create the grouping (the "Sort & Group" button, select the data field, check the box to show group header). I also don't have access to SPD2013 yet, still using SPD2010.
Also, I'm using IE8, upgrading to a more modern browser isn't an option. I haven't tested this on other browsers.
