The PPP documentation indicates that when the refund process did not work, the provider must respond with a null to this field, and also when the refund must be performed manually, the code field must have the value “refund-manually”.

The problem is that each triggers a refund, causing it to be doubled.

Send code="refund-manually" and settled=null in the settlement response with PPP.

Do not send "refund-manually" in the code field, rather just send the settled as null.