The comments issue is resolved!
I figured out that it was because the too-good-to-be-true Zero Spam plugin was interfering with the processing of comments. The reason was that it doesn’t work with the Jetpack engine, which takes care of everything else, including the comment form. Between the two evils (letting a little spam into comments held for moderation and letting go of everything else including stats,) I chose to keep Jetpack and bid goodbye to Zero Spam.
If you have a self-hosted blog and fall for the perfection that Zero Spam offers, be careful. Your commenters with get a message, “There was a problem processing your comment.”
Now the Comments are working fine. I’m dying to know what you think about:
Anandhotep has sent me to apologize to everyone who tried leaving a comment and then helped me with my shenanigans, as I tried to figure out. THANKS 😀