Are you sure you are using the correct spelling of the name when setting the field?  Curious because you said "Originator" but later said "OriginatorId"

When you use a column ''Originator in your design, the problem is present. So I am wondering if this is a Nintex Bug ?

I've run into issues in the past with certain "reserved" column names and have observed the same thing.  For example list lookup fails if you have a column name such as DisplayName that is the same as an item property in Sharepoint.

Hi Mike, yes got that same feeling too with reserved fields. A column like Originator is a standard column every user would define as valid column in his/her design isn't it ?

I think that Nintex must address this as this frustrates like hell and did take me roughly 2 hours to correct.

Without checking, I say it certainly sounds like one.  Why not just change the column name to something else and test, see if you get better results?

Yes we called ite Requester but if you have loaded a history of 2000 records and need to run a workflow to fill that field again, I am not going to love that extra work :-)