Please run the following code


import javafx.application.Application;
import javafx.geometry.Insets;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.control.Slider;
import javafx.stage.Stage;

public class SliderTest extends Application {

    @Override
    public void start(Stage stage) {

        Group root = new Group();
        Scene scene = new Scene(root, 150, 100);
        stage.setScene(scene);

        double x = 1.e-4;
        Slider s = new Slider(0., x, x / 3);
        s.setPadding(new Insets(20, 20, 20, 20));
        s.setShowTickLabels(true);
        s.setShowTickMarks(true);
        s.setMajorTickUnit(x / 3);

        root.getChildren().add(s);
        stage.show();
    }

    public static void main(String[] args) { launch(args); }
}

all the slider tick labels are "0" - see "nok1.png"

then try x = 1.e-3 => "nok2.png"

JDK9 b132 was used. OS - Windows 7