Combobox filter does not work after removeAllItems

Originally by m1kah

Steps to reproduce

1. Press tab
2. Press enter to click "Change options" button
3. Press tab
4. Type a
5. Verify that "abcde" is shown in suggestion box
6. Press shift+tab
7. Press enter
8. Press tab
9. Type a

-Expected behavior*
"abcde" is shown in suggestion box

-Actual behavior*
All values are shown, there is no filtering. Combobox filtering
text field has value 'a'.

Use backspace to remove 'a' and type it again, now filtering works.

You can use this piece of code to reproduce the issue

@Override
protected void init(VaadinRequest vaadinRequest) {
    ComboBox comboBox = new ComboBox();
    Button button = new Button("Change options");
    button.addClickListener((e) -> {
        comboBox.removeAllItems();
        comboBox.addItem("abcde");
        comboBox.addItem("qwerty");
    });
    setContent(new FormLayout(button, comboBox));
}

Imported from https://dev.vaadin.com/ issue #19702

Start with the supplied ComboBox reproduction and trace filtering after the button calls removeAllItems() and adds the two replacement items. Confirm the suggestion box still filters for the existing text "a" after the options change, and add or run a regression check if the relevant test location can be found.