Joining the thread to share insights about the account on your report, @User_1234.

Thank you for sharing the steps in generating your report and the screenshots on how it looks like. Ideally, the COGS account increases after selling an item and not when building the assembly.

Moreover, I have here an article that discusses the details of your account while tracking inventory: Understand Inventory Assets And Cost Of Goods Sold Tracking.

On that same page, I've also found out the credit amount of COGS in an assembly is a portion of the items used while building. One of our members, @KarriW, discussed it and shared an example here: Build Assemblies and Cost of Goods Sold.

I'm adding this article with the topics that allow you to skip manual tracking and focus on making your own products: Track the Products you Manufacture in QuickBooks Desktop Premier, Enterprise, or Accountant.

If you have any other questions aside from building an assembly, please let me know in the comments below. I'll be here to lend a hand. Take care and stay safe!