Those links work but aren’t oneboxed.
All the current steps to embed Instagram posts are discussed here: Configure an app token for Instagram oneboxes - #12 by Iceman
And it indeed works, as I did it on my forum: Forum updates & features - Rework of several menus - #14 by Canapin - Forum Feedback - Unicyclist.com
Instagram posts aren’t oneboxed on meta, and I’m just wondering if it’s intentional or not.