Hi NU-LTGx,

It's nice to see you here in the Community again. I'd be glad to lend a hand with Reconciliation Reports in QuickBooks Online (QBO). 

In order to undo an entire reconciliation, you will need to manually edit each transaction to change its reconciled status. Here's how:

1. Select the Gear icon then choose Chart of Accounts. 
2. Find the row of the account and choose View Register.
3.  Locate the transaction you need to edit. 
4. In the reconcile status column, continue to select this field to change the reconcile status.
5. Click Save. 

I've included a brief video as a demonstration:

If you created an adjusting entry during this reconcile, you will need to find it and delete it, with the following article containing additional information on this: How do I find Previous Reconciliation Adjustments?.  Also, I'm including an article with further insight on the process of undoing a reconciliation: Change a Transaction Status or Undo a Reconciliation.

Lastly, if there are a great number of transactions that would require editing and you have an accountant connected with your QuickBooks Online account, you may want to ask them to undo the reconciliation for you. However, it's recommended to look at the following article before doing so: Avoid Undoing a Reconciliation.

Please know that I'm only a post away if you have any questions. Have a great rest of the week.  
 

Thank you so much!