Can someone help me to see how the QB picks the value/cost of inventory when we pass sales invoice, in my case, the cost of the item is zero, but still cost is assigned

Hello there, habib.

It is our priority to ensure this gets resolved. Beforehand, can you please share a screenshot of your invoice and Inventory Valuation Detail report? Doing so helps us further check the cause of this issue.

I'll look forward to hearing from you soon. I'm always here to help you out.