Discovered the same thing as @xyzzy today. This is from a brand new sync account created yesterday! Come on Opera, at least let us know if there is some kind of work around for this annoying broken sync feature. At least introduce some kind of tool (as @raaimin2 suggested) that makes it easy to remove duplicates.

Had to handover my old laptop due to new job. Next issue led me to this forum post. All bookmarks that was part of the bookmarks bar seems to be lost. The Import function doesn't list the Opera account as an option. The bookmarks are not visible at my Opera account. I don't have access to my old machine any more. Are the bookmarks in the Opera cloud just not visible? How long after logging on a new machine and Opera account until all bookmarks have been synced?

Previous laptop: Opera 30.0
New laptop: Opera 30.0