Autocorrect not working, even if I also enable Predictive Text -- in Sonoma

Hi. I'm on a 2023 MBP running Sonoma 14.5.

I turned off autocorrect spelling and predictive text a while back, finding the latter annoying. This is done in Settings.

Now I can't get autocorrect spelling to work at all, in Apple apps and non-Apple apps.

I've clicked on the Settings/Keyboard/Input (weird place to find this, incidentally)/ and checked the check boxes to enable autocorrect spelling. Restarted. Didn't work.

After reading another conversation here on Apple Support, I saw that people are being forced to additionally enable Predictive Text if they want Autocorrect Spelling to work. Well, that sucks!

But when I went back in and re-enabled Predictive Text along with Autocorrect Spelling, and restarted, I found that neither of them is working.

I feel like I've done All The Things but don't know what to do next. In the olden days I'd zap the PRAM!