Hi @Phillipsca,
This must be a custom field created by your implementing partner. Basically when a sales document (e.g. Order) has been deleted or posted it creates a what we called sales archive e.g. Sales Order Archived.
It uses a TRANSFERFIELD method that copy all record given since it has the same field structure and data type.
"Order Created By" field from sales header archive table uses the same field id as "Order Created By" from sales header and this must be a programming or designing issue. I would suggest to reach out on your implementing partner for this to resolve.
However you can try disabling the Archive feature by going to the Sales and Receivables Setup > Archiving Fast Tab > Archive Orders - disable.
