net value zero in second invoice

hi all.

I am facing an starnge issue in my current project. the net value is coming as zero if I am creating more than 1 invoice for my sales order.

the scenario is - we have a third party sale

case 1:-

Sales order (5 Qty) -- PO (5 Qty) -- MIGO (5 Qty) -- Sales invoice (5Qty) -

Pricing OK, no issue at all

Case 2:-

Sales order (5 Qty) -- PO (5 Qty) -- MIGO (5 Qty) -- Sales invoice 1 (3 qty) --- pricing OK, net value OK

Sales invoice 2 (2 qty) --- pricing OK, net value NOT OK (zero)

if I create one invoice for a sales order there are no issues, but if I create multiple invoice, then except very first invoice, everything else is coming as net value "zero".

And strangely, all the other condition type and condition values are same and correct. I could not find out why this is happenning for 2nd invoice onwards.

Please suggest.

Regards,

Biplab Rout