You can update stock in QBO and depending on the method used, sometimes the last updated timestamp is not updated. This means that on the next sync with QBO we do not update the stock levels on our side. We have tried raising this with QBO, but they do not seem to want to make the appropriate change on their side to ensure the last updated timestamps are being adjusted as expected. It would be a nice addition if we could create a system option that would allow our customers to select if they want a full product import ran every day or week. We could queue this after running daily maintenance to help ensure that their stock levels are remaining up to date and accurate.