customer A made a partial payment for Inv 2, 50%, on Oct.

I have matching the Oct bank statement.

customer A made a full payment for inv 1 on Dec.

Now, I would like to change the payment details for Inv 1, from "deposit to" account A to B.

the system says

This transaction has been matched with a statement line. Hence, the fields which affect the transaction amount cannot be modified.

and I have to delete the payment for Inv 1, and record the payment again, in order to deposit to account B.