updated:

Confirmed. I was not able to delete this YouTube.com post.

I click the delete button, I confirm, and yet it is still on the site.

As a sanity check, I later created two posts linking to other domains and I was able to delete them.

Somehow, I am flagged by some anti-spam system into not being able to delete my own posts to only YouTube.com. However, those YouTube.com posts are public.

Is this system working as intended?