The issue is related to WHT tax data.
Suppose there are 3 line items,
L1 - WHT Code XX
L2 - WHT Code XX
L3 - WHT Code XY
Here system only caluculate WHT code of L1 and L2 and Ignores L3 WHT in calculation.
XY is defined, as when I use only XY in all 3 line item system calculate tax.
Is it even possible to define two different WHT code in one Invoice doc?