This is a recent regression, maybe related to CategoryAxis changes. See broken and working screenshots. The Broken is drawn using only about half the X axis width.

Code to make chart

        final Random RANDOM = new Random(29782198273l);
        String[] years = {"2001","2002","2003"};
        String[] series;
        if (simple) {
            series = new String[]{"A","B","C"};
        } else {
            series = new String[]{"A","B","C","D","E","F","G","H"};
        }
        CategoryAxis xAxis = new CategoryAxis(FXCollections.<String>observableArrayList(years));
        NumberAxis yAxis = new NumberAxis();
        yAxis.setLabel("Units Sold");
        ObservableList<BarChart.Series> barChartData = FXCollections.observableArrayList();
        final double negative = -500;
        for (int s=0; s<series.length; s++) {
            ObservableList<BarChart.Data> sd = FXCollections.observableArrayList();
            for(int y=0; y<years.length; y++) {
                    sd.add(new BarChart.Data(years[y], negative+(2000*RANDOM.nextDouble())));
            }
            barChartData.add(new BarChart.Series(series[s],sd));
        }
        Node barChart = new BarChart(xAxis, yAxis, barChartData);