CVD gl hitting in grn and j1iex during Imports

Dear Experts,

I am facing different issue during imports, in a single SA/PO CVD crediting and adding to material cost.

here is the process

1.SA/PO

2.Commercial invoice:

Customs clearing GL dr

CVD clearing GL dr

Commercial office Cr

(entry is correct)

3.GRN

Stock GL dr

Gr/Ir clearing cr

CVD clearing cr

Customs Clearing cr

(means CVD adding to material cost which is not correct)

4.Excise invoice post:

BED,AED dr

CVD clearing cr

(entry correct)

we have checked every thing but not getting it ,can some one help on it how system posting at both times.