I have looked at this JSFiddle where scrollbar example is shown. It has 9 entries.I have same number of entries for A in my JSFiddle and still the scrollbar doesn’t shows up in my case. Please explain. Please click on consolidate button before checking the dropdown against A
You should set auto dropdown height to false of the ComboBox. autoDropDownHeight: false, (or just remove this property, and this will set default value – false)
I have tried both the approaches and it still doesn’t shows the scroll bar. Here is my updated JSFiddle with the property you mentioned completely removed.