Write a calculated value to database

Hi - new to Retool. I have a table with two fields each containing numbers and a third field which I have set to calculate the product of multiplying the first two numbers - all good and it works when I edit the numbers in the table and save the changes. But ... the calculated field isn't writing back to the database. I gathered that additional calculated columns aren't part of the bulk update by ID GUI function ... so I added the multiplication formula into the actual column (and it looks like it is working as it updates AFTER I press the save changes button) but it obv isnn't writing back as it only updates after the bulk update has executed. How do I get the calculated result to write back to the database?
Huge thanks in advance
Steve

Can you share a screenshot of the table and the GUI config...