I have a folder with 8,000 large files. While I was working (but nowhere near the folder nor the files contained therein) I suddenly started getting notifications of "Smart Sync Download" and that all the files were "Syncing and Opening"
I have not accessed any of these files, although it's acting as if I had manually clicked each one, or perhaps changed the status to "Local file"
Changing the root folder to "online only" is not stopping the process.