Credit note not getting created from Order Management

I want to create CN for an invoice from Order Management. but when try to do so system is giving an error as # The total amount of your credit memo cannot exceed the balance of the debit item it is crediting

I checked amount on original invoice and SO trying to create CN are same.

There are no applications applied to this original invoice. Txn setup is correctly, as per system we are not allowing over application.

Still the CN not creating. can you help