I would goto https://sync.opera.com/web/ and reset your sync data to wipe out all your synced data to start over. I'd also start with a new profile in Opera. Close down Opera and delete the profile folder. See the URL opera://about for the path. Then, start Opera, enable/log into sync, set what you want synced and then use Opera. Then things should work as long as nothing outside Opera is interfering.
S