Full novel project open (~120,000 words, plus supporting docs - 14.5Mb). Had multiple documents selected & viewed as a Scrivening.
Switched away to do some other things.
Switched back. From that point on I could not change the document that was displayed. Clicking on any document in the Binder did not affect which document was displayed.
Seeing as how you have the editor header bar hidden (View ▸ Editor Layout ▸ Header View), it’s hard to tell whether you have Navigate ▸ Editor ▸ Lock in Place enabled at the moment, but that would certainly intentionally do what you are demonstrating here. Another potential culprit is Navigate ▸ Binder Selection Affects ▸ None, but that one has no keyboard shortcut that could be accidentally triggered, so it is less likely the culprit.
I’m fairly sure I didn’t have Lock In Place enabled (at least, not purposely), and I’ve never touched the other setting. I restarted Scrivener, and it was fine after that, which is why I leaned towards an obscure bug rather than a setting (assuming that most of these settings would normally persist between application launches).
I’ve not managed to reproduce it (un)fortunately, so I’m unable to give further information. I’ll keep an eye out. If it happens again, I’ll go through the menus & reveal the Header so you can see everything.
Yeah, if it happens again I’d see what’s it looks like with the header bar turned on. Otherwise if it is only happening in one project, and it keeps happening repeatedly, it might be worth resetting its display settings.
Lock in Place wouldn’t be cleared in a reload by the way. That’s as persistent a setting whether you’ve split the editor or not, etc.