Hi there, Emma. Before we go deeper into troubleshooting steps, let's try a couple of fixes that usually resolve these types of display issues.

After creating the invoice, I suggest refreshing your browser page. Then, go back to the Products and Services list to see if the quantity has updated. If refreshing doesn't work, it's possible that the link between that invoice and your stock levels encountered an issue during the save.

In this case, I suggest opening the invoice > click More at the bottom > and select Delete. Then, recreate the invoice from scratch. When doing so, please double-check that the invoice date is not earlier than the As of Date you set when you first created the inventory item. QuickBooks won't deduct stock for a sale that happened before the item existed in the system.

If you need anything else related to QuickBooks, don't hesitate to reply here. We're here to help.