All the DVDs I create with Movie Edit Pro 15 Plus, go to the main menu after each chapter finishes. I tried in several DVD models and in my two computers and it is the same.
Are you sure you're referring to chapters (as in the terminology of the DVD-authoring system)? Do you possibly have several movies in this Movie Edit Pro project, each of which is represented by an entry in the main DVD disc menu? In this case, jumping back to the main menu is a default setting, but you can change it. Just right-click on the entries/thumbnails for the movies in the preview screen of DVD-authoring section and open the properties for each movie. You will find a selection for the action at the end of the movie. Here you can pick to just move on to the next movie. I guess this setting might make sense, if you have arranged your project in such a manner that the movies are meant to be played in succession (like chapters).