Scrollbar click closes the poplist/list of value inside a parametrised popup

[swetakanodia]

I have a parametrised popup region. It contains a ListOfValue input. On typing in LOV filed, the list occurs. If the list is too long or too wide, scrollbar appears.
On clicking on scrollbar to scroll, the listofvalue disappears.
This is happening in IE9,10,11 but not in firefox,chrome, etc.

Kindly help in fixing this.