In Client Matter Enquiry the Statement and Statement date can be added to check if the item has been reconciled, follow the below steps to add these in:
Over the Ledger detail right click and select Choose Columns.
In the list on the left find Statement and Statement Date either double click them or highlight and click the right arrow.
Check to see if the item that you have reversed has already been reconciled, if it has it will have a Statement number and Statement date.
This mean that it actually left the bank or the system thinks it did.
Check if it really did leave the bank on your online banking or if it has been reconciled in error.
If it really did leave the bank then you need to repost it to the ledger.