Process of debiting the supplier on quality issues

Scenario 1) Supplier will issue credit note, and yes GST should be added in the credit note.

Scenario 2) Same treatment.

Make reference of section 34(1) of CGST Act which is as follows-

34. (1) Where a tax invoice has been issued for supply of any goods or services or both and the taxable value or tax charged in that tax invoice is found to exceed the taxable value or tax payable in respect of such supply, or where the goods supplied are returned by the recipient, or where goods or services or both supplied are found to be deficient, the registered person, who has supplied such goods or services or both, may issue to the recipient a credit note containing such particulars as may be prescribed.

Yes please let me know their view!