I know ways to correct the category for a transaction mistakenly categorized.
You can change the credit card payment category from the Chart of Accounts or from the Banking tab. Here's how you can change it from the COA:
From the left pane, click on Accounting.
Select the Chart of Accounts.
Select the bank account and hit View register.
Locate and select the transaction. Then, change the Category from the drop-down.
On the other hand, here are the steps to follow if you'd like to change it from the Banking tab:
From the left pane, click on Banking.
Select the bank account.
Go to the Categorized tab, then find the credit card payment transaction and click Undo.
After that, go to the For Review tab. Then, locate and select the transaction and change the category.
Editing a reconciled transaction can still be done as long as the Total Amount, Date, and Bank Account stays the same. It will only cause discrepancies or changes on your Profit and Loss report if you changed the transaction type. In cases like this, you'll have to manually unreconciled the month when the transaction is dated.