@hnktong,
Sync has not been re-enabled in v 1.3.115 yet. We’re still hammering out the issues and want to ensure that they are all resolved before we flip that switch back on.
@macman,
You can try what @barfburglar suggested, but note that it will delete any of your browsing data along with it. Ensure that you backup anything that you don’t want to lose before performing this action.