How to get next and previous post links, alphabetically by title, across post types, in a shortcode

I need next and previous post links in a single post page using a “page-builder” type of CMS—specifically the DIVI theme by Elegant Themes. So, I need the links to be able to appear using Shortcodes, as the controls in the template, along with a lot of the default template stuff, are hidden when you use the page builder. AND, my client needs to be able to manipulate where in the page layout the next/previous post controls appear, depending on the post type, as it’s a portfolio site and “sculptures” get treated with a different layout than “paintings”, if that makes sense.

wp_delete_auto_drafts() deletes links in menus

Since yesterday the wp_scheduled_auto_draft_delete cron job somehow deletes all page entries from our menus. All entries in the table wp_postmeta with meta_key = '_menu_item_object' and meta_value = 'page' get deleted in the process. By tracing back the DELETE query I found out that the menu entries are deleted by a function called _wp_delete_post_menu_item. I got the following stacktrace for that function: