Hi AllView,
Due to the difference in the platform, some data will not be carried over during export. However, this is rare to register transactions since they are supported for export.
What we normally suggest to compare the balance sheet and profit and loss reports on both QuickBooks Desktop and QuickBooks Online after export. Have you been to this step?
If there is a big difference in the register amounts, you can export the file again. But first, you want to run Verify and Rebuild data tools to make sure it has no issues before exporting.
If there's only a small difference, you can trace them and recreate the missing ones. You can compare transactions per month.
Here's an article about reconciling an account for hour reference: https://intuit.me/2TnHnZJ
We're just right here if you need more help to trace your transactions.
