PO Revision Causes Recalculation of Amount adding Tax

Hi Gurus,

We have noticied recently, upon modification of the approved PO causes recalculation of the amount and adds the tax (GST 6%).

Approved Purchase Orders that are revised recalculates its amounts and adding Tax to the order causing a discrepancies. Workaround is business user will have to raise a dummy transaction to do miscellaneous adjustment. Need assistance on prevention or permanent fix to avoid POs doing recalculations and adding tax.

Kindly help us how to avoid this recalculation, I mean to avoid including the GST amount during recalculation of the PO amount.

Thank you.

Regards,

Venu