X Axis tick marks in bar chart with multiple data series

I have a bar chart that takes a single time interval value as the X axis property and a comma-separate list of properties as the Y-axis property.  At the moment it plots multiple bar charts for all Y-Axis properties and a single time interval, all on the same graph.  I also roll up a set of error bar values into a global array and pass this into the bar chart.

I have to provide the list of  Y properties as a global, comma separated list of strings that is then expanded, i.e. \\\$(Property) .  The problem I have is that the X-Axis tick marks are not displayed, which is not helpful.  How do I get these to display?

Clyde