When I switch to the child theme I am working on, the main menu uses the page names instead of the names that I gave it in the Appearance > Menu options. Happened to anyone else?
The custom menus assigned to Menu Locations (in the Appearance, Menus, Manage Locations tab) are saved per theme. So when you switched to your new theme, you lost that assignment. Go to the Manage Locations tab and select your custom menus again.