Delivery Note Delivered item must be reduce in inventory stock

Delivery Note Delivered item must be reduce in inventory stock

When I create any Delivery note with product like mobile

In our stock if it was 10 Unit

I sold thru invoice, 4 unit
And thru Delivery note, 2 Unit and I also change Delivery note status as delivered

So in my stock it should display remaining 4 unit

But write now it display 6 unit only.

Please help me for that

Because when I creating new invoice it display 6 unit in stock but actually in my physical stock its only 4.

So I miss guide with stock display