Import -> Import fail for demographics data update

Company - Austin for hspl, City of bellevue for hspl

1)Login with Partner
2)Select company
3)Create demographic template
4)Import the file -> Import done successfully for multiple employee
5)Updated last name of 1 st employee from file -> Import done successfully
6)Updated last name for all 3 employee from file -> Import failed

Note : Same scenario worked properly on LB(QA caiso for hspl)
With same security customization i.e Data update for all 3 Employee -> Import done successfully

Please note : Once Import is failed, even new employee cannot be inserted.In each and every attempt import gets failed