Reports total row sums inappropriate columns

I believe the below is incorrect somehow…

the rate/net rate columns has nothing to show if calculated, it need not to be summed.

if we show item properties, the rows Net total and Grand total sums the rows with no logic, it should sum only one value for each invoice.

if we remove the item properties the invoice showed in now row, so the sum becomes correct.

any suggestions, or do I miss something ?