Good afternoon, @DanceBC.
It's great to see you back in the Community. I can provide you with some information to help you out.
Since the transaction is already reconciled, all you would need to do is undo the transaction from the reconcile and then delete it.
Here's a guide that will give you details instructions on how to do this action successfully in your account: Undo or remove transactions from reconciliations in QuickBooks Online.
Come back if you have any other questions or concerns about your account. I'm only a post away if you need me. Take care!
