How to default the Financial Transaction in FTR_EDIT

Dear Experts,

After creating a transaction via t-code FTR_CREATE, we can edit it via t-code FTR_EDIT. For my EHP7 client, when I edit a transaction, the option "default entry financial transaction" actually is not defaulted according to the transaction No I input. And all of the buttons are active for this transaction.

I know SAP can realize that the financial transaction type can be automatically determined in t-code FTR_EDIT, but I do not know how to set or configure it.

Could you please guide me how to fix it once I input the transaction no the field financial transaction can be automatically determined.

Thank you very much!

Eric