Issue:

When you select a table row, and then further click inside the selected row but in a different column (so you're selecting a different cell, basically click back and forth between the two columns in the test case but within the selected row), the SelectedItem gets set to null.

Code to reproduce:

import javafx.application.Application;
import javafx.application.Platform;
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.property.StringProperty;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.scene.Scene;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableView;
import javafx.scene.control.cell.PropertyValueFactory;
import javafx.stage.Stage;

public class TableSelectionBug extends Application {

@Override
public void start(final Stage stage) throws Exception {
TableView<OneRow> table = new TableView<OneRow>();
table.getSelectionModel().setCellSelectionEnabled(false);
table.setEditable(false);

table.getSelectionModel().selectedItemProperty().addListener((prop, ov, nv)-> System.out.println("Selected item is: " + nv));

final ObservableList<OneRow> tableData = FXCollections.synchronizedObservableList(FXCollections.observableArrayList());
for (int i = 0; i < 30; i++) {
tableData.add(new OneRow("Name #" + i, "Surname #" + i));
}

TableColumn<OneRow, String> col1 = new TableColumn<OneRow, String>("First Name");
col1.setCellValueFactory(new PropertyValueFactory<OneRow, String>("firstName"));
TableColumn<OneRow, String> col2 = new TableColumn<OneRow, String>("Last Name");
col2.setCellValueFactory(new PropertyValueFactory<OneRow, String>("lastName"));

table.setItems(tableData);
table.getColumns().add(col1);
table.getColumns().add(col2);

Scene mainScene = new Scene(table, 800, 600);
stage.setScene(mainScene);

stage.setTitle("Select a row in the table, then click around on different columns within the row.");
stage.show();

stage.setOnCloseRequest(e -> {
Platform.exit();
System.exit(0);
});

}

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

public class OneRow {

public OneRow(String firstName, String lastName) {
setFirstName(firstName);
setLastName(lastName);
}

private StringProperty _firstNameProperty;

private StringProperty _lastNameProperty;

public StringProperty firstNameProperty() {
if (_firstNameProperty == null) {
_firstNameProperty = new SimpleStringProperty();
}

return _firstNameProperty;
}

public void setFirstName(String firstName) {
firstNameProperty().set(firstName);
}

public String getFirstName() {
return firstNameProperty().get();
}

public StringProperty lastNameProperty() {
if (_lastNameProperty == null) {
_lastNameProperty = new SimpleStringProperty();
}

return _lastNameProperty;
}

public void setLastName(String lastName) {
lastNameProperty().set(lastName);
}

public String getLastName() {
return lastNameProperty().get();
}

}
}