You can use the Transaction Detail Report to verify if there are transactions that were changed or modified. Let me help you with the steps.
Click Reports, and then Custom Reports.
Click Transaction Detail.
Change the Date From = the earliest QuickBooks date (or leave blank). Then, the Date To = the date of last reconciled statement.
Click the Filters tab, select Account = the account being reconciled. In Entered/Modified Date From = date of the last reconcile, Date To = Today.
Once you've identified, you need to make the necessary corrections. If you have a new transaction added to the reconciliation period or have modified previously reconciled transactions, you may need to do mini-reconciliation.
Another report that we can run to identify reconciliation discrepancies and fix transactions is the Missing Checks Report. This report helps you to find absent transactions. Here’s how to run the report:
Choose Banking then clicks Missing Checks, from the Reports Menu.
Select the Appropriate Account then click OK.
Analysis of the report for transactions that don’t match your bank statement.
If you’re still unable to locate the discrepancies, I’d recommend contacting the support team. They have more tools like the screen sharing which will help you investigate and fix the issue. Here’s how to reach them:
Click Help at the top.
Select QuickBooks Desktop Help.
Click Contact Us.
Give a brief description of your issue and click Continue.
Select Talk to a Specialist.
Drop by again if you have other questions about QuickBooks.