It really depends how your javascript component is built but if the content of your quickpopup is outside the vaadin-overlay then the click is “ignored” (which is the idea of a modal dialog).
One solution for “overlay/popup” component inside a component is to put the content (html code) inside the dialog (next to your component). I’m guessing it’s not inside the dialog-overlay and I think you don’t have any option to do that with quickpopup.
Another workaround can be to add this css in your content of the quickpopup: (you need to change the name of the css class)