Forgot to set productnumber to primary key in integration job. Fixed, but subsequent runs cause primary key error

Hello.

I defined an integration job, but forgot to check off ProductNumber as primary key.

The job imported products, and created system primary keys for each, and all products got a row with ProductNumber and LANG1

I then realized my mistake, and checked off ProductNumber.

But now I get a Primary key error, and in the error message its doing a where on productnumber = NULL

For some reason the job doesnt match on product number, and therefore does not understand that this is an UPDATE not an INSERT

Does anyone have any theories as to why this happens?

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