Unable to update and primary address if it is a primary flag is true using rest API

Header: Upsert-Mode : true

Rest API: https://xxxx-test.fa.us1.oraclecloud.com/crmRestApi/resources/11.13.18.05/contacts/1148115/child/Address/

Payload:

{    

"SourceSystem": "Onekey",   

"SourceSystemReferenceValue": "ADD00017",   

"PrimaryFlag": true,   

"PartySiteEO_Workplace_c" : "ADD00017-update1",   

"Country" : "KW"

}

Expectation: Want to update the address either the primary flag is true/false

Actual: we are able to update the address only if the primary flag is false

error:

A record with the value Onekey, ADD00017 already exists. Enter a unique value.

Regards

Mohammed Hyder