Wicket Behavior is working in some cases, and is not in others

Question

I have implemented a wicket behavior as shown below:

@Priority(100)
public class MouseOverTextBehavior extends Behavior {

    private final String description;

    public MouseOverTextBehavior(String description) {
        this.description = description;
    }

    @Override
    public void onComponentTag(Component component, ComponentTag tag) {
        super.onComponentTag(component, tag);
        // Set the title attribute
        tag.put("title", description);

        // Create a JavaScript function that will be executed when the mouse
        // pointer enters the component
        String jsFunction = String.format(
            "$('<div class=\"description\">%s</div>').appendTo('body');"
                    + "var labelRect = $(this)[0].getBoundingClientRect();"
                    + "var popupRect = $('.description:last')[0].getBoundingClientRect();"
                    + "var popupTop = labelRect.top - popupRect.height - 10;"
                    + "var popupLeft = labelRect.left + (labelRect.width - popupRect.width) / 2;"
                    + "$('.description:last').css({ top: popupTop, left: popupLeft });",
            description != null? description.replace("'", "\\'"): null
        );

        tag.put("onmouseover", jsFunction);
        jsFunction = "$(this).prev('.description').remove();";
        tag.put("onmouseout", jsFunction);

        // Set the position: relative
        tag.put("style", "position: relative;");
    }
}

Then i tested it for being added to some Component like: Label I.E:

Button button = new Button("myButton");
button.add(new MouseOverTextBehavior("This is a button"));
add(button);

And it is working fine.

The problem is that behavior is working fine on some cases like the example above, and not working in other cases like the following case:

add(newReferenceCodeLabel("id").add(new MouseOverTextBehavior("Show this message!!"))); 

Knowing that:

private Label newReferenceCodeLabel(final String id) {
        

return new Label(id, new AbstractReadOnlyModel<String>() {

            private static final long serialVersionUID = 5340631294817017953L;

            @Override
            public String getObject() {
                final AfElement afElement = getAfElement();
                String referenceAeCode = afElement.getReferencedAeCode();
                if (afElement instanceof AeProductPromotion
                        && afElement.getProductCode().equals(referenceAeCode)) {
                    referenceAeCode = null;
                }
                return referenceAeCode;
            }
        });
    }

I want to know the reason why this behaves like that, and how to fix it?