beas Journal entries showing current Warehouse Unit

The Problem is in the Journal Entries of an Article in BEAS
We have an Articel with diffrent kg as Purchase Unit and m as WarehouseUnit.
The Customer now want to change the Warehouse Unit into the Purchase Unit (from "m" to "kg")
The Problem now ist that in the Historie of this Article in the Journal Entries in BEAS the Warehouse Unit has changes to the new Unit which can not be correct because then there would be a false Article History.
Example: the Unit was changed by the 20.05.2019 and an delivery was made at the 19.05. in SAP everything is ok but in the BEAS Journal Entries from the Article History is shows this article from 19.05.2019 with the new Warehouse Unit instead of the old one becuase at this Date there was still the old Warehouse Unit.