During playback, the default was for the cursor to stay always onscreen, with the pages moving forward automatically. But now the pages stay fixed, and so the cursor moves off-screen. How do I reestablish the default? (Not sure what I did to affect the default in the first place…..)
It’s a setting: Preferences → Play → Playhead. I think it’s “follow playhead” or something.
There’s also a switch at the bottom of the document window.

That’s what I already have checked. So, it should work.
update: I restarted my computer, and that has fixed the problem. FYI