The Created By field is blank when a draft is created using the app Maintain Bill of Material
Maintain Bill Of Material
SAP S/4HANA Cloud
The draft data is not persisted and would be blank until it is saved.
This is not a bug but standard behavior.
App ID, F1813, BOM , KBA , PLM-FIO-BOM , Fiori UI for Material BOM , LO-MD-BOM , Bills of Material , How To