How to increase the bar height of the parent row in xViZ Gantt Chart ?

xViz Community How to increase the bar height of the parent row in xViZ Gantt Chart ?

I am using the xViZ Gantt chart in which there is a two level heirarchy. I ma unable to increase the width of the top level or parent level bar.

Here i am trying to increase the height of the grey bars to match the green bars. I tried increasing the height using Chart Options -> Actual bar height but it does not work.

This is an urgent issue and any help would be appreciated.