ADDITIONAL SYSTEM INFORMATION :
Running on Windows 10, OpenJDK Runtime Environment AdoptOpenJDK (build 15.0.1+9)

A DESCRIPTION OF THE PROBLEM :
Using a touch-enabled device (or add the JVM argument -Dcom.sun.javafx.touch=true), the virtual flow scrolls all the way to the left when the scrollbar disappears. It allows scrolling to the right however it only stays for a second or two before the horizontal scrollbar gets reset to 0 (when the scrollbar disappears from inactivity, it gets reset to 0). From closer inspection of the code, it seems this is caused by the method updateHbar(), in .../modules/javafx.controls/src/main/java/javafx/scene/control/skin/VirtualFlow.java. The method checks if the hbar is visible and if it is not, it gets set to 0

if (hbar.isVisible()) {
                clipView.setClipX(hbar.getValue());
            } else {
                // all cells are now less than the width of the flow,
                // so we should shift the hbar/clip such that
                // everything is visible in the viewport.
                clipView.setClipX(0);
                hbar.setValue(0);
            }



STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
With the parameter (-Dcom.sun.javafx.touch=true) as a JVM argument, run an application containing a table view, where the window is smaller than the table, thus causing a horizontal scrollbar, drag the scrollbar all the way to the right and release it and wait until the scrollbar disappears.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
When the scrollbar disappears, the table should remain as it was in the position you scrolled to.
ACTUAL -
When the scrollbar disappears, the table is scrolled to the beginning (hbar value of 0).

---------- BEGIN SOURCE ----------
import javafx.application.Application;
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.property.StringProperty;
import javafx.beans.value.ObservableValue;
import javafx.scene.Scene;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableView;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;
import javafx.util.Callback;
import java.util.ArrayList;

public class Main extends Application {

    int columns = 5;
    int numRows = 15;
    StackPane root = new StackPane();

    @Override
    public void start(Stage primaryStage) {
        Scene scene = new Scene(root, 200, 400);
        primaryStage.setTitle("Hello World!");
        primaryStage.setScene(scene);
        primaryStage.show();
        TableView table = getNewTestTableview();
        root.getChildren().add(table);
    }

    public TableView<StringProperty[]> getNewTestTableview() {
        TableView<StringProperty[]> tableView = new TableView<>();
        for (int i = 0; i < columns; i++) {
            final int colIndex = i;
            TableColumn<StringProperty[], String> col = new TableColumn<>();
            col.setCellValueFactory(new Callback<>() {
                @Override
                public ObservableValue<String> call(TableColumn.CellDataFeatures<StringProperty[], String> param) {
                    return param.getValue()[colIndex];
                }
            });
            tableView.getColumns().add(col);
        }

        ArrayList<StringProperty[]> rows = new ArrayList<>();

        for (int i = 0; i < numRows; i++) {
            StringProperty[] row = new StringProperty[columns];
            for (int j = 0; j < columns; j++) {
                row[j] = new SimpleStringProperty("Row " + i + " Col " + j);
            }
            rows.add(row);
        }
        tableView.getItems().addAll(rows);
        return tableView;
    }

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        launch(args);
    }

}

---------- END SOURCE ----------