There's a possibility that the affected account of the product/service item is set to an expense account. Let's review this item to correct your data in QuickBooks.
1. Click the Gear icon in the upper-right corner and select Products and Services.
2. Look for the item and click Edit.
3. Make sure the information in the Income account field is correct.
4. You'll have an option to update the account in historical transactions.
5. Click Save and close.
If you're referring to something else, any additional information and screenshots you can provide would be much appreciated. Thank you in advance.