Selected Grid row Combobox fieldgroup binding fail

Hello everybody
This is my Problem with Vaadin 7.6.3
I have a Grid, with a Beancontainer source and bind the selected grid row with a beanfieldgroup to
textfields and a Combobox.
Now, if you have a field in the grid equal “CC/44”, and this field has been bound with the Combobox,
and the Dropdownlist has the same string “CC/44”, the combobox refresh fail after the second
click to this grid row.
Do I something wrong, or is this a combobox bug?
Please take the sample code below and check it out.
Thank you very much.

public class MyUI extends UI {

    final BeanContainer<String, Person> personBeanContainer = new BeanContainer<>(Person.class);

    // Bind forms to beans and manage validation and buffering
    BeanFieldGroup<Person> formFieldBindings;

    protected void init(VaadinRequest vaadinRequest) {
        final VerticalLayout layout = new VerticalLayout();
        final TextField name = new TextField("Name:");
        final TextField born = new TextField("Born:");
        final ComboBox testCombo = new ComboBox("Test:");
        // Put some example data in it
        personBeanContainer.addBean(new Person("Nicolaus Copernicus", "1543", "W5"));
        personBeanContainer.addBean(new Person("Galileo Galilei", "1564", "CC/44"));  // String with slash
        personBeanContainer.addBean(new Person("Johannes Kepler", "1571", "Q10"));
        // Add some items with a given ID
        testCombo.addItem("CC/44");   // Same slash String in the Dropdown List --> Combobox refresh fail

        // Create a grid
        Grid grid = new Grid();
        grid.addSelectionListener(event -> {
          BeanItem<Person>item = personBeanContainer.getItem(grid.getSelectedRow());
          formFieldBindings = BeanFieldGroup.bindFieldsBuffered(item.getBean(), this);
          formFieldBindings.bind(testCombo, "test");
          formFieldBindings.bind(name, "name");
          formFieldBindings.bind(born, "born");

        HorizontalLayout hLayout = new HorizontalLayout(grid, new FormLayout(name, born, testCombo));


    public class Person implements Serializable {
      String name;
      String born;
      String test;
      public Person(String name, String born, String test) { = name;
        this.born = born;
        this.test = test;
      public String getName() {
        return name;
      public String getBorn() {
        return born;
      public String getTest() {
        return test;
      public void setName(String name) { = name;
      public void setBorn(String born) {
        this.born = born;
      public void setTest(String test) {
        this.test = test;
    @WebServlet(urlPatterns = "/*", name = "MyUIServlet", asyncSupported = true)
    @VaadinServletConfiguration(ui = MyUI.class, productionMode = false)
    public static class MyUIServlet extends VaadinServlet {


But it works if you have items with same id in the combobox. In your example you only have the middle item the same id and the other items are different.

Hi Johannes
You are right, it works if all combobox items have a correspond grid field value,
and it works if all combobox items are different in the grid field.

But if the items are mixed (some are equal some are different) the binding fail.
Why is the grid value no more bound to the combobox?