www.wysiwygwebbuilder.com

I have a external link set up in my navigation bar, and have it set to "open in a pop up window" set at: width 600 height 800.

It's opening in a new window, but in a full maximized screen.

Any ideas?

Thanks

To be able to help you I need to see what you have done.

Note that browser may choose to ignore the size properties, based on user preferences (unrelated to WWB).
For example., mobile browsers do not support popup windows.
https://developer.mozilla.org/en-US/doc ... indow/open

Have you tried using a lightbox. I use Fancybox and Magnific Popup in Desktop and mobile without too much hassle.