In Dropbox app options, in selective sync, I've re-enabled some folders. They were indexing/downloading and eventually finished. Dropbox app status shows now: "up to date" BUT the downloaded files are still offline!
My settings are: New files default: Available offline.
Is it because these files were synced long time ago when I had settings "New files default: Online-only"?
The only solution I see now is to copy the whole offline folder to a new one, wait until Dropbox re-uploads it and remove the old buggy one.