“Post Comment” results in message disappearing (not posted, not saved as draft, no message why).
I guessed it was due to a link to a site on the undocumented list of “forbidden” web sites, so I posted a link to a page that links to it ( https://cse.engin.umich.edu/academics/undergraduate/computer-science-lsa/ → link to a page with the “CS-LSA Program Guide” for Michigan’s CS major that is probably the “forbidden” web site – why would such a thing be “forbidden”?).
But it is really user-unfriendly just to make the post disappear without giving any indication why it disappeared. A better result would be to keep it as draft and pop up a reason why the comment cannot be posted (e.g. “forbidden web site”).