How to sync content title with "synchronize translations" module?
Possibly this is because titles do not get translated in a site using the i18n module. And that is most often because of the Title module that has not been enabled. From the module's project page (bold markup added here):


  After enabling the module as usual, visit the Manage fields page of the content type, taxonomy vocabulary or "comment type" which you wish to replace fields of and click the replace link. That's all.