The link I posted specifically states-
"I want to be able to have drop down menus coming down from these specific pages, not just the Word Press "Pages" in general link."
You then claim to have added that functionality.
And when I originally installed this plugin, I was able to select just a single page to display on the menu. The dropdown was then built from its child pages. This allowed for me to have a menu with links such as "About," "Contact," "Products" etc.
After upgrading the plugin to the latest, the Admin section displayed "?p=40" instead of "Contact" and the menu displayed nothing. I could not re-select the pages.
Not really sure how I was able to do this before if, as you claim, the functionality was not there in the first place..?