Shortlink Doesn’t Include Domain

Creating a new post and publishing it, the shortlink is created but only to the post name portion of the URL. For instance, if the post is viewed at https://site.com/page-here/ the YoURLs shortlink will point to only page-here, not to the full URL. The domain is dropped.

Have I misconfigured something in the plugin or WP? My YoURLs install works just fine other than this one site.