In Editable Templates , unlocking and adding the components to allowed components , after that locking back the templates load the actual page content in template and resetting it back to initial content.
As per editable template policy, once a component that already contains content is unlocked, this content will be moved to the initial branch and the editable property is set to true. Initial content is something which will be shown on a page upon a page creation. So you should unlock the component to make it reflect on the page.