UOM for safety days' supply

Hi Experts,

I have an issue with the UOM for safety days' supply. I have already configured the following

in Planning Area - Safety Days' supply -> UOM is not ticked

in table /SAPAPO/TSPAPLOB, I changed the UOM Plan to '10'

in Planning Book, decimal places for this KF is '0' (Value for UOM table is not selected)

Once I open the planning book, the Safety Days' Supply is in "D" however, when I tried to load a selection profile, the unit of measure changes to 'KG'. I have not inputted any data in this key figure so would like to ask what else could I have missed?

Thanks in advance.

Ria