I had entered a vendor bill for the incorrect amount and paid the incorrect in QB desktop. I didn't physical pay the bill wrong it was for the correct amount, I posted the payment wrong

I entered a vendor bill for the incorrect amount $276 and posted the payment for the incorrect amount $276.  I didn't physically pay it wrong, just the posting.   The bill and payment should be $277.44.  In order to correct this I change the invoice amount and the payment.  However it created a payment due of $1.44 and a credit of $1.44.  I am just wondering why QB Desktop did that?