You mean your Joomla menu? Set your Joomla menu module to display on all pages and it shouldn't be an issue. Your save registration page is using your CB profile menu item so you can assign the module to that. Your URL directly to a plan doesn't have an Itemid so you can't assign modules to it unless you add an Itemid to the URL.

See my reply above as I've already explained what menu item it's using and you'll have to assign your module to that menu item if you want your menu module displayed on that page. I don't recommend doing menu assignment this way though. You should be reversing it by selecting menu items it shouldn't display on rather than what menu items it should display on as it avoids these problems.