I have noticed that when you create a new static page it is not displayed in Navigation Menus’s options. only default items are available.
To create a new menu item you should click “Add item” ( Navigation Menus >>> Navigation Menu Items) and then chose Remote URL >>> “Link to any URL on another site” >>> … and add URL of the page you have created.
After that you should edit directly Primary or User menu … your page with URL will be available
