series data not getting stored

Hi,
I have created series similar to history, history override and adjusted history.
say inv units, inv units override and final inv units.

final inv units = inv units if there is no value in 'inv units override'.
Created a series with update field and server expression.

I can able to view the desired output in WS, but data in final inv units are not getting stored into respective column of base tables.

Can anyone tell me what may be the problem/issue?

Thanks