[v11] importing item Variants - "Duplicate entry" error

I try to update a bunch of Item Variants, which where previously created in the GUI, with the data import tool. I have applied some changes to the item_name, name & item_code columns

The import (Update Records) fails with error messages for each single item as the below

('Item Variant Attribute', u'1eedac4fb6', IntegrityError(1062, u"Duplicate entry '1eedac4fb6' for key 'PRIMARY'"))

can anyone make sense of this and advise how to get around this problem?

I do not think this is related but the updated values contain / instead of -

I am facing the same issue were you able to solve it?