copies of events appearing continually
It doesn't feels like a CiviCRM Core problem to me but I don't know what else it could be either. 

The "Copy of" seems to indicate that it use the CRM_Event_BAO_Event::copy as if used by the Copy action in manage event page.

You may check for any custom code that could contains CRM_Event_BAO_Event::copy or something like that.

You could also try to disable CiviCRM extensions or Joomla extensions one by one and see if it keeps happening