Let me address your concern about fixing the incorrect reconciled transactions.

First, you’ll need to unreconcile those transactions that need to be corrected. Once you’ve already unreconciled them, you can unmatch the specific transaction from the transfer and match it with the correct expense transaction.

Finally, re-reconcile the bank account to keep […]

Resolution for 'already reconciled issue: 'Back in May of 2017 I accidentally put a transaction under transfer instead of expense if I unmatch this what will it do since it is already reconciled?' available: Yes.

The already reconciled issue or error code is a known issue in Quickbooks Online (QBO) and/or Quickbooks. Support for this issue is available either by self-service or paid support options. Experts are available to resolve your Quickbooks issue to ensure minimal downtime and continue running your business. First try to resolve the already reconciled issue yourself by looking for a resolution described in the article. If it is a complex already reconciled issue or you are unable to solve the issue, you may contact us by clicking here or by using other already reconciled support options.

For more information about resolving issues related to already reconciled in Quickbooks/QBO or to get support for the issue 'Back in May of 2017 I accidentally put a transaction under transfer instead of expense if I unmatch this what will it do since it is already reconciled?', click the link below: