I don't understand your menu setup, sorry. For guest only menu use Joomlas built in guest ACL so a menu module is only available to a guest user. A single menu module with ACL for individual menu items would also circumvent issues like this. We don't have a menu endpoint for the saveregisters page so it's not going to have its own specific menu item. Best I can suggest is create a Joomla menu item to CBs registration page and see if it'll utilize its Itemid instead of the profile menu id.