A DESCRIPTION OF THE PROBLEM :
When I replace all Series with new series, the new series' data-elements get wrong style-classes for default-color. For the first 8 series, the numbering is correct, for all other, the numbering is shifted.
See here for a detailed description:
https://stackoverflow.com/questions/51893749/javafx-xycharts-weird-behaviour-on-replacing-all-series

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
import javafx.application.Application;
import javafx.beans.InvalidationListener;
import javafx.scene.Scene;
import javafx.scene.chart.NumberAxis;
import javafx.scene.chart.ScatterChart;
import javafx.scene.chart.XYChart;
import javafx.scene.control.Button;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;

import java.util.ArrayList;
import java.util.List;

public class ChartSeriesReplacing extends Application {
    @Override
    public void start(Stage primaryStage) throws Exception {

        VBox root = new VBox();

        ScatterChart<Number, Number> chart = new ScatterChart<>(new NumberAxis(), new NumberAxis());

        Button refresh = new Button("Refresh");

        refresh.setOnAction(clicked -> {
            List<XYChart.Series<Number, Number>> seriesList = new ArrayList<>();
            for (int i = 0; i < 15; i++) {
                XYChart.Series<Number, Number> series = new XYChart.Series<>();
                series.setName(i + "");

                XYChart.Data<Number, Number> data = new XYChart.Data<>(Math.random(), Math.random());
                int finalI = i;
                data.nodeProperty().addListener(__ -> {
                    if (data.getNode() != null) {
                        data.getNode().getStyleClass().addListener((InvalidationListener) ___ -> {

                            // System.out.println("[pre] Data #" + finalI + ": Style = " + data.getNode().getStyleClass());

                            // DIRTY-WORKAROUND-SOLUTION:
                            // (has to live in listener, otherwise the chart erases any custom styling on adding... :-/ )
                            // String colorString = "default-color" + finalI % 8;
                            // data.getNode().getStyleClass().removeIf(s -> s.startsWith("default-color") && !s.equals(colorString));
                            // if (!data.getNode().getStyleClass().contains(colorString)) {
                            // data.getNode().getStyleClass().add(colorString);
                            // }
                            // --------------------------

                            System.out.println("[post] Data #" + finalI + ": Style = " + data.getNode().getStyleClass());
                        });
                    }
                });
                series.getData().add(data);

                seriesList.add(series);
            }
            System.out.println("-----------------");

            // What I tried:
            // 1)
            chart.getData().setAll(seriesList);

            // 2)
            // chart.dataProperty().setValue(FXCollections.observableArrayList(seriesList));

            // 3)
            // chart.getData().clear();
            // 3a)
            // chart.getData().addAll(seriesList);
            // 3b)
            // seriesList.forEach(series->chart.getData().add(series));
        });


        root.getChildren().add(chart);
        root.getChildren().add(refresh);

        primaryStage.setScene(new Scene(root));
        primaryStage.show();
    }
}


// --> hit "refresh" multiple times

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
[post] Data #0: Style = chart-symbol series0 data0 default-color0
[post] Data #1: Style = chart-symbol series1 data0 default-color1
[post] Data #2: Style = chart-symbol series2 data0 default-color2
[post] Data #3: Style = chart-symbol series3 data0 default-color3
[post] Data #4: Style = chart-symbol series4 data0 default-color4
[post] Data #5: Style = chart-symbol series5 data0 default-color5
[post] Data #6: Style = chart-symbol series6 data0 default-color6
[post] Data #7: Style = chart-symbol series7 data0 default-color7
[post] Data #8: Style = chart-symbol series8 data0 default-color0
[post] Data #9: Style = chart-symbol series9 data0 default-color1
[post] Data #10: Style = chart-symbol series10 data0 default-color2
[post] Data #11: Style = chart-symbol series11 data0 default-color3
[post] Data #12: Style = chart-symbol series12 data0 default-color4
[post] Data #13: Style = chart-symbol series13 data0 default-color5
[post] Data #14: Style = chart-symbol series14 data0 default-color6

for every click on "refresh"
ACTUAL -
for 1st click as expected.

for 2nd click:

[post] Data #1: Style = chart-symbol series1 data0 default-color0
[post] Data #2: Style = chart-symbol series2 data0 default-color1
[post] Data #3: Style = chart-symbol series3 data0 default-color2
[post] Data #4: Style = chart-symbol series4 data0 default-color3
[post] Data #5: Style = chart-symbol series5 data0 default-color4
[post] Data #6: Style = chart-symbol series6 data0 default-color5
[post] Data #7: Style = chart-symbol series7 data0 default-color6
[post] Data #8: Style = chart-symbol series8 data0 default-color7
[post] Data #9: Style = chart-symbol series9 data0 default-color7 <-- from here on shifted!
[post] Data #10: Style = chart-symbol series10 data0 default-color0
[post] Data #11: Style = chart-symbol series11 data0 default-color1
[post] Data #12: Style = chart-symbol series12 data0 default-color2
[post] Data #13: Style = chart-symbol series13 data0 default-color3
[post] Data #14: Style = chart-symbol series14 data0 default-color4
[post] Data #0: Style = chart-symbol series0 data0 default-color0

for 3rd click:

[post] Data #1: Style = chart-symbol series1 data0 default-color0
[post] Data #2: Style = chart-symbol series2 data0 default-color1
[post] Data #3: Style = chart-symbol series3 data0 default-color2
[post] Data #4: Style = chart-symbol series4 data0 default-color3
[post] Data #5: Style = chart-symbol series5 data0 default-color4
[post] Data #6: Style = chart-symbol series6 data0 default-color5
[post] Data #7: Style = chart-symbol series7 data0 default-color6
[post] Data #8: Style = chart-symbol series8 data0 default-color7
[post] Data #9: Style = chart-symbol series9 data0 default-color5 <-- !!
[post] Data #10: Style = chart-symbol series10 data0 default-color6
[post] Data #11: Style = chart-symbol series11 data0 default-color7
[post] Data #12: Style = chart-symbol series12 data0 default-color0
[post] Data #13: Style = chart-symbol series13 data0 default-color1
[post] Data #14: Style = chart-symbol series14 data0 default-color2
[post] Data #0: Style = chart-symbol series0 data0 default-color0

---------- BEGIN SOURCE ----------
import javafx.application.Application;
import javafx.beans.InvalidationListener;
import javafx.scene.Scene;
import javafx.scene.chart.NumberAxis;
import javafx.scene.chart.ScatterChart;
import javafx.scene.chart.XYChart;
import javafx.scene.control.Button;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;

import java.util.ArrayList;
import java.util.List;

public class ChartSeriesReplacing extends Application {
    @Override
    public void start(Stage primaryStage) throws Exception {

        VBox root = new VBox();

        ScatterChart<Number, Number> chart = new ScatterChart<>(new NumberAxis(), new NumberAxis());

        Button refresh = new Button("Refresh");

        refresh.setOnAction(clicked -> {
            List<XYChart.Series<Number, Number>> seriesList = new ArrayList<>();
            for (int i = 0; i < 15; i++) {
                XYChart.Series<Number, Number> series = new XYChart.Series<>();
                series.setName(i + "");

                XYChart.Data<Number, Number> data = new XYChart.Data<>(Math.random(), Math.random());
                int finalI = i;
                data.nodeProperty().addListener(__ -> {
                    if (data.getNode() != null) {
                        data.getNode().getStyleClass().addListener((InvalidationListener) ___ -> {

                            // System.out.println("[pre] Data #" + finalI + ": Style = " + data.getNode().getStyleClass());

                            // DIRTY-WORKAROUND-SOLUTION:
                            // (has to live in listener, otherwise the chart erases any custom styling on adding... :-/ )
                            // String colorString = "default-color" + finalI % 8;
                            // data.getNode().getStyleClass().removeIf(s -> s.startsWith("default-color") && !s.equals(colorString));
                            // if (!data.getNode().getStyleClass().contains(colorString)) {
                            // data.getNode().getStyleClass().add(colorString);
                            // }
                            // --------------------------

                            System.out.println("[post] Data #" + finalI + ": Style = " + data.getNode().getStyleClass());
                        });
                    }
                });
                series.getData().add(data);

                seriesList.add(series);
            }
            System.out.println("-----------------");

            // What I tried:
            // 1)
            chart.getData().setAll(seriesList);

            // 2)
            // chart.dataProperty().setValue(FXCollections.observableArrayList(seriesList));

            // 3)
            // chart.getData().clear();
            // 3a)
            // chart.getData().addAll(seriesList);
            // 3b)
            // seriesList.forEach(series->chart.getData().add(series));
        });


        root.getChildren().add(chart);
        root.getChildren().add(refresh);

        primaryStage.setScene(new Scene(root));
        primaryStage.show();
    }
}
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
uncomment the lines titeled dirty workaround.

FREQUENCY : always