Tooltips sometimes do not appear

Reported via https://vaadin.com/directory/component/tooltips4vaadin/discussions

<java.version>1.8</java.version>
<vaadin.version>14.7.2</vaadin.version>

@Route
public class MainView extends VerticalLayout {
    
    public MainView() {
        for (int i = 0; i < 10; i++) {
            Button myButton = new MyButton();
            Button show = new Button("Show", e -> myButton.setVisible(true));
            add(new HorizontalLayout(show, myButton));
        }
    }
    
    private static class MyButton extends Button implements HasTooltip {
        public MyButton() {
            setIcon(VaadinIcon.VAADIN_H.create());
            setTooltip("Tooltip");
            setVisible(false);
        }
    }
}