Problem with pop ups on a specific website.

I have been having a problem with my book club website. when I order a book there is a type of pop up that lets me know the book was placed in my cart. It works fine in IE which I have always hated and don’t like to use. but… even though I have pop ups ok in settings, it never pops up. Is there an add on or setting other than the pop up setting I need to set? Thank you