Product quantity not updating when bill is entered

We can confirm whether the product you added in Item details is designated as Inventory and is correctly mapped in your product settings. QuickBooks Online requires this specific item type to automate inventory adjustments.

If your quantities are still not updating, fix the background mapping by following these steps:

1. Navigate to the Gear icon, then select Products and services.
2. Find the item and click Edit.
3. Ensure the Item Type is set to Inventory (Non-inventory and Service items do not track quantities).
4. Verify the Inventory Asset Account is correctly mapped to your asset account, and the Expense Account is mapped to Cost of Goods Sold.

If you still need further assistance, don't hesitate to reply below!