New JetPack Breaks Shortlinks for Custom Post Types

A number of WPSSO Core customers using JetPack have reported that shortlinks no longer work for Custom Post Types (CPTs). According to JetPack, this is a feature, and PHP code specifically for this JetPack feature must be added to your functions.php file — or an additional property added to the Custom Post Type definition. Unless you have made these PHP code changes, JetPack will break the WordPress wp_get_shortlink() function for all Custom Post Types. Because of this new JetPack feature, the current version of WPSSO Core may show a warning on Custom Post Type editing pages that the post shortlink is empty — which also prevents WPSSO Core from checking the current post webpage for duplicate meta tags. Additionally, the WordPress “Get Shortlink” button on post editing pages and the link rel="shortlink" HTML tag in webpage headers, will be missing.
The upcoming version of WPSSO Core checks for empty values returned by the wp_get_shortlink() function and provides a correct shortlink URL. This not only addresses the new Jetpack feature, but also fixes incorrectly coded themes that disable the link rel="shortlink" HTML tag by returning an empty
Source: https://managewp.org/articles/16718/new-jetpack-breaks-shortlinks-for-custom-post-types

source https://williechiu40.wordpress.com/2017/11/28/new-jetpack-breaks-shortlinks-for-custom-post-types/