Double clicks are being captured as single click :(

In fxml file:

<Button fx:id="A_button" onMouseClicked="#buttonAClicked">
In the controller

private void buttonAClicked(MouseEvent mouseEvent) {
    if (mouseEvent.getButton().equals(MouseButton.PRIMARY)) {
        if (mouseEvent.getClickCount() == 2) {
            System.out.println("Double clicked A_button");
        }
        if (mouseEvent.getClickCount() == 1) {
            System.out.println("Single clicked A_button");
        }
    }
}
Unfortunately I am finding that double click is not being caught - only single clicks. In the debugger, click count is 1.