How to update a testcaseresult (executionresult) with a different iteration (testphase) using the REST API

Hi I am using Postman and the REST API to update a testcaseresult (aka executionresult) with a different iteration (aka testphase).

I will leave out the authentication piece as this is working as per the guidance here: Using Postman to issue a HTTP(S) request (ibm.com)

We are on version 6.0.6.1 of RQM and Jazz.

Firstly, I perform a GET to pull the xml for an testcaseresult (aka executionresult) :

https://{server:port}/qm/service/com.ibm.rqm.integration.service.IIntegrationService/resources/{project}/executionresult/urn:com.ibm.rqm:executionresult:1111

This works and brings back my testcaseresult (aka executionresult) :

<?xml version="1.0" encoding="UTF-8"?>

<ns2:executionresult...> 

<ns2:testphase href="https://{server:port}/qm/service/com.ibm.rqm.integration.service.IIntegrationService/resources/{project}/testphase/urn:com.ibm.rqm:testphase:72"/>

Secondly, I take that payload and modify the testphase to :

<ns2:testphase href="https://{server:port}/qm/service/com.ibm.rqm.integration.service.IIntegrationService/resources/{project}/testphase/urn:com.ibm.rqm:testphase:227"/>

Which is the testphase I want and is in the correct test plan schedule.

Lastly, I then use this as my body payload for a PUT with the same url as above. The return is a 200 Okay:

<entry xmlns:rqm="http://schema.ibm.com/rqm/2007#executionresult" xmlns="http://www.w3.org/2005/Atom">

    <rqm:resultId xmlns:rqm="http://schema.ibm.com/rqm/2007#executionresult">1111</rqm:resultId>

    <rqm:resultItemId xmlns:rqm="http://schema.ibm.com/rqm/2007#executionresult">{someStateId}</rqm:resultItemId>

    <rqm:resultExternalId xmlns:rqm="http://schema.ibm.com/rqm/2007#executionresult">urn:com.ibm.rqm:executionresult:1111</rqm:resultExternalId>

</entry>

This tells me that it has worked but it did not update the iteration (aka testphase).

Interestingly, this is not shown as an editable or linked item in the UI:

Please note that I can successfully update other fields in the testcaseresult (aka executionresult).

Any light anyone can shed on this would be much appreciated

Regards,

Danny.