Reconciled items are appearing as unreconciled in the following months bank rec

Hi AAmery, 

Welcome to the Community Forum. I apologize for the delayed response.

Based on the current information, it will be difficult to find what caused these transactions to re-appear. I believe the best course of action is to undo the reconciliation month by month to check if the transactions match the bank statements. Also, you can check if the opening balance of the bank account to see if the value is correct on the conversion date. 

Let us know if you require further assistance.

Thanks,
Genreve