YouTube-embedded videos work 100% but video links from Facebook or Instagram Reels are not accepted.
Important: it does work with Updates...
This link is the "copy link" shared link from Instagram: https://www.instagram.com/reel/DFiPkZyvyNp/?utm_source=ig_web_copy_link
But this is the link shared from Instagram to email:
https://www.instagram.com/reel/DFiPkZyvyNp/?igsh=ZGUzMzM3NWJiOQ==