Hello.
I'd be more than happy to work with you on fixing the reconciled transactions, and removing the duplicate records.
We can undo those reconciled transactions, then delete those duplicate records in QuickBooks. We would essentially go back to square one, so your balances are correct for the current and the next accounting period.
To undo the transactions:
- Go to your Chart of accounts, then click on View register for the bank account in question.
- Locate one of the reconciled transactions for the period you want to undo. Open a record to start the edit.
- Under the checkmark column, click the R box until it is blank.
- Once done, click Save.
- Do this for all the transactions within the period you want to undo.

Alternatively, if you happen to have an invited accountant, we can let them undo your reconciled transactions in batches. We can share this article with them if they need help: Undo a client’s reconciliation in QuickBooks Online Accountant.
If you need more help with this, or if you're unsure about the corrections, I would recommend consulting an accountant. They'll guide you through the process and ensure your balances are accurate for all accounting periods.
I would also suggest reviewing your bank statement, then cross-referencing it with the records in QuickBooks. That way, we would be able to tell if there are duplicate transactions or not.
If you need to follow up on your customers about their due balances in the future (for payments on the next accounting period), I'll share this article with you: Create and send customer statements in QuickBooks Online.
You can always post here again if you have other concerns about your reconciled entries. Drop the details below if you have questions about your reports, tax forms, and employees (for payroll). I'm here to help.