Updating table values - history settings

I have loaded a table with some initial data  (== initial stoock). The key is quiet simple  Company, Warehouse and Item

Now I want to update the amounts every day so that it reflects the actual stock level of data day

The initial load was done from one source , the updates come from another sources 

History settings  have natural jkey set , and all non lookup fields are updsated  (type 1)

Nevertheless the record is not updated 

Any idea ‘why’ the update is not working