Khürt, I’ve figured it out then. I’d seen the issue I initially thought you were having a few dozen times.
Your actual issue is far more subtle, but is a known issue with WordPress. Because the title of my original post contains the glasses emoji (indicating it’s a “read” post, or something that I read and made some sort of comment on), WordPress “eats” or filters out all of the data you’re trying to save. If you put the URL in again and then retrieve the data, but this time delete out just that pesky emoji, it should save properly as you expect it. Let me know if that doesn’t work.
I’ve noticed the issue before and reported it officially here: https://github.com/dshanske/indieweb-post-kinds/issues/117