:onclick is triggered even when a box is overlayed on an eventbox

[OBLIXi-ON]

I've a created a powermenu in eww which contains basic options. The structure is something like this:

(defwindow sessionpopup
      ...
      (sessionpopup_widget)
)

(defwidget sessionpop_widget[]
      (overlay (eventbox :onclick "eww close sessionpopup")
               (box ...)
)

The issue here is :onclick is triggered even when I'm clicking over the box. I just want the :onclick event to be triggered only when I click on the eventbox excluding the box area. Is there any way to do so?