Why Composite Items Not Updating Inventory Levels After Sale?

Why Composite Items Not Updating Inventory Levels After Sale?

After I complete a sale I'm noticing that the main Composite Item is reducing its available level but the associated items are not reducing their available level, they are staying the same.

Reading the FAQ's on Composite Items I see the following line:

"Action No.1 - Sales: When you sell a composite item (raise a sales order, invoice, package, ship), the stock automatically goes down. This is effected appropriately based on your chosen mode of stock tracking under organization profile of the settings module"

I have looked at the "chosen mode of stock tracking under organization profile of the settings module" and tried checking the box for both 'Physical Stock' and 'Accounting Stock' but when I complete the sales process the associated items are not reducing.

I did not opt for the 'Box/Unbox' method because I want this reduction to happen automatically on completion of a sale to reduce the risk of human error

I'm sure I've overlooked something here but I am at a loss to know what I'm doing wrong.

I have followed the tutorial but I cannot get the associated items to reduce.

Can someone enlighten me as to what I am doing wrong?