This is a regression from RT-36663. It is caused by a negative stripFactor.

Here's a test code:

    @Override
    public void start(Stage stage) throws Exception {

        NumberAxis axis1 = new NumberAxis(0, 100, 10);
        axis1.setTickUnit(0.25);
        NumberAxis axis2 = new NumberAxis(0, 100, 10);
        LineChart chart = new LineChart(axis1, axis2);
        VBox vb = new VBox();

        XYChart.Series serie = new XYChart.Series("serie", FXCollections.observableArrayList(new XYChart.Data(1, 1)));

        chart.getData().add(serie);

        vb.getChildren().add(chart);

        Scene scene = new Scene(vb, 200, 200);
        stage.setScene(scene);
        stage.show();
    }