This site, unlike my others, is almost entirely made of posts. The other sites are pages. And for some reason or another, the site was wonky using the same theme with same settings as the others. Gave up trying to figure it out and installed another. This one has excerpts (which I dislike). And the sidebar is missing from the front page (whyyyyyy?). But I’m done messing with it for now. If you come back later and see the sidebar on the main page, you’ll know I won the battle.
In other words, what a pain in the ass WordPress themes can be.