If manage user’s access level has not changed, you should be able to edit transactions from the bank (check) register in new QuickBooks.
From the blue navigation bar on the left > select Transactions > select Registers > Locate and double click on the bank account to edit
It will take to “Bank Register” screen. Highlight entry, make change and save. Four tabs bar will also open. If you click on “Edit” button, it will take to originally entry form.
You cannot change the “type” of expense transaction. For example, you cannot change from “Expense” type “Bill” type transaction. For that you will need to delete the transaction and create new type of transaction.