DNG CSV Import Issue with User Data Types

Given an artifact attribute using a data type with a base type of "user", can that attribute be successfully updated via CSV import in DNG 6.0.2?
I tried to do this and found it accepted the full name of the user as a valid input for the attribute but would assign no value to the attribute and treated the data as a null input. Is that a bug and/or is there a proper way to do it? I will not accept the user name (login id) as a valid input.
Accepted answer

It works fine in my RDNG 6.0.3 iFix003 environment. I believe you are seeing the below defect.
107696: Round-trip CSV import clears User type attributes
It was fixed in RDNG 6.0.3. If you want to backport it to 6.0.2, you need to contact IBM Support for such request.