invoice reversal for delivery cost conditions thr MR8M posting to PRD account

Hi All

Below is scenario -

Invoice for delivery (multiple GRN) cost posted & below are the entires

Cr Vendor 120 USD

Dr Clearing 120 USD

When this invoice is reversed through MR8M we got below entries

Cr Clearing 50 USD

Cr PRD account 70 USD

Dr Vendor 120 USD

Exchange rate is same in bothe documents.

Will anyone guide me analysing the issue why system posting entries to PRD while reversing the delivery invoice

Regards,

Rakesh