Listview event bubble

Hi, I am using a listview with a custom template binding some event listener to the inner elements. I have both singletap event listener on the inner element of the listview as well as the outmost container(in my case, a window) and I want use the event bubbled to the window to perform some action. However, the window cannot receive the bubble event from the inner element(But when I remove the eventlistener on the inner element, it can!) I really appreciate any thought that may causing the problem, thanks!

Here is the sample code I am using:

in index.xml

<Alloy>
    <NavigationWindow>
        <Window id="win" backgroundColor="#fff">
            <ListView id="listView" defaultItemTemplate="template">
                <Templates>
                    <ItemTemplate name="template">
                        <ImageView bindId="pic" id="icon" />
                        <Label bindId="info" id="title" onsingletap="singletap"/>  
/*whenever I remove this event listener, I will be able to receive singletap event on window. However if I left it here, I cannot get the event bubbled to window*/
                        <Label bindId="es_info" id="subtitle" />
                    </ItemTemplate>
                </Templates>
                <ListSection headerTitle="Fruit / Frutas">
                    <ListItem info:text="Apple" es_info:text="Manzana" pic:image="/apple.png" />
                    <ListItem info:text="Banana" es_info:text="Banana" pic:image="/banana.png" />
                </ListSection>
                <ListSection headerTitle="Vegetables / Verduras">
                    <ListItem info:text="Carrot" es_info:text="Zanahoria" pic:image="/carrot.png" />
                </ListSection>
            </ListView>
        </Window>
    </NavigationWindow>
</Alloy>

function singletap(e){
    console.log("single tapped on title");
    e.cancelBubble = false;
}
$.win.addEventListener("singletap", function(){
    console.log("received singletap event at window");
});
 
if(OS_IOS){
    $.index.open();
}