I appreciate you for joining the thread, @pirraglia.

You can update the opening balance through the register. I can guide you on how.

1. Open your QuickBooks Online account, then click on Accounting at the left pane.
2. Select Chart of Accounts.
3. Find and open your account.
4. Search the account register for the opening balance entry. It should be labeled Opening Balance Equity with “Opening Balance” in the Memo column.
5. In QuickBooks, select the opening balance entry to expand the view.
6. In the Deposit column, edit the balance so it matches your bank records.
7. Hit Save to record the changes.

Once done, you can start undoing the 2 months reconciliation. You can either invite an accountant to perform the process or edit the individual transactions manually. 

Here's an article you can read more about undoing reconciliations in QuickBooks Online.

Moreover, you can open this link to know more about modifying the account's opening balance.

For additional hints about banking and reconciliation, you can also check out the topics from our help articles: Find help with bank feeds and reconciling accounts.

Please feel free to get back to me here for any additional questions about QuickBooks or reconciliation. I always have your back. Thanks for dropping in, and cheers for more success!