Thanks for coming back. Let me help you share some insights about reconciling your account in QuickBooks Online (QBO), accountant46.

I appreciate you for performing the recommended solutions provided by my colleague to get this sorted out. If you are trying to access QBO with more than one browser tab simultaneously, here's the correct way to work in more than one tab:

1. While signing in to QuickBooks Online in one tab, go to the browser address bar. 
2. Highlight then copy the entire web address.
3. Open a new browser tab.
4. Paste the web address into the new tab then press Enter. The home page of your company will now load in the new tab.

Then, try inviting your accountant to review your books in QBO again. If you reconciled a transaction by mistake, we can remove individual transactions from the reconciliation. Then, reconcile them back to get a new report. Keep in mind, even small changes can unbalance your accounts. To minimize the impact, we can only unreconciled one transaction at a time. If you need to completely start over, I'd suggest reaching out to your accountant since they have a tool to undo everything in one go.

Unreconciling your transactions mean replacing the R (reconciled) mark with C (cleared) or blank. You'll want to do this to all transactions within the period covered in the report. When you know which transaction you need to change, here's how to edit and unreconciled the transaction:

1. Go to the Accounting menu, then select Chart of Accounts under Your Company. 
2. Select the account you're working on, and click on View Register.
3. Choose the transactions you want to unreconcile.
4. Keep on clicking the R status until it shows blank or cleared (C).
5. Click Save.
6. Close the account register.

Here's an article you can refer to for more details about undoing and removing transactions from reconciliations in QuickBooks Online. If you encounter any issues while reconciling, you can check out this article to learn about fixing it: Fix issues at the end of reconciliation in QuickBooks Online. 

Feel free to check out this article for more information about the reconciliation workflow: Learn the reconciliation workflow in QuickBooks.

You can always update us after performing the steps as I want to ensure this is resolved for you. I'll be standing by for your response. Have a great day and keep safe.