Differences in sales order total and AR invoice total

Hi Team,

Customer copied a sales and enabled the "Freeze price" and "Freeze Tax" check box. Then changed the order quantity from 2 to 1.

Even though they changed the quantity sales order is still calculating price for 2 quantity where as in AR invoice price is calculating for 1 quantity only.

Now there is a differences in order total and AR invoice.

Please help let us know.

Thanks,
Sandhya