This is on Windows.
Whenever I close, or open, a particular project, the binder view defaults to “updated documents”. I want it to always show the full binder contents. This happens even if I have made no changes to either the project or to the synced backup. It’s only an annoyance, but I wish I understood why it’s happening.
I wonder if deleting or moving my backup so it’s forced to create a new backup might help? If nobody has a definitive answer I’ll try that. Thanks.
Forget what I said about syncing the backup. The glitch seemed to have been between the project and its actual file location – doing an all-new “Save As” seems to have fixed the issue. 
This topic can be closed, though I would still be interested if there’s an expert explanation for this behavior.
On the Mac, the Scrivener → Settings → Sharing → Sync pane has an option to automatically show the “Synced Documents” collection after a sync. I’m not sure where the corresponding Windows setting is, but that’s probably the one you want.
This sounds suspiciously like OneDrive (…toRuleThemAll™) again…. That digital imp causes Scrivener no end of trouble because of what assumptions it makes about file usage and which files to keep onboard and which to ship off to the cloud, even when you probably have told it to leave things alone. So, it would not surprise me that your helpful Redmond daemon is moving things around its throwing things off as you suggest.
I believe this is intended behavior. I see it on the Mac when I switch between machines. I don’t normally work on Windows, but on Mac the binder view has a different colored background and looks more like a popup rather than a binder view, and can be easily dismissed with a little x in the upper right corner. On Mac it’s only intended as a heads up, a ‘Hey, boss, this is what I changed’ sort of message.
As @kewms suggests there is a setting to toggle.
File → Options → Sharing icon → Sync tab → External Folder Sync heading
You should see a checkbox called ‘Automatically show the “Updated Documents” collection after a sync’. Clear that checkbox and it should stop doing what bugs you.