Thanks for the explanation.
I found that I had missed two points:
I had not added property “showArrow: true” as you suggest and this now works.
But also the width of the fourth panel was clipping the arrows.
The arrow seems to be at an absolute location on the tab and may be clipped by parent div width.
Firefox Firebug helps in troubleshooting.
In your jqxNavigationBar online demo when I right clicked on a navigation bar
and “Inspect Element using Firebug” I saw reference jqx-expander-arrow. Hence my question.
I’ll be more careful in setting panel widths to avoid clipping.