User is trying to sync expense entries from CORE to QuickBooks Online. However, instead of the Cost Amount of expenses, the Charge Amount is synced over.
This is controlled by the option Do not send purchase tax in QuickBooks Sync Detail > Send > Expense Entry. If this option is unchecked, the Charge Amount is synced over along with the purchase tax amount. Otherwise, the Cost Amount is synced without any purchase tax. In order to sync the Cost Amount, you need to check this option. Check CORE Help Center for details.