I had this issue. This may be due to the settings. In Quickbooks. Go to the app in QBO and navigate to settings. Under basic settings it shows the account mapping for your sales. You can assign where you want your sales to land. I used product income for items and square income for unmatched items. If you have these settings - and you have square income it's due to unmatched items. If this is the case confirm the names are identical in both product lists. The QBO sales sync by product name. Hope this helps!