As from patch G402 a SOAP request cannot be delegated to a second userver

As from patch G402 a SOAP request cannot be delegated to a second userver.

A Uniface service is called by a SOAP client such as SoapUI. The SRD delegates
this request to an urouter,
who passes it to an userver to activate the service.

However when that userver delegates the activation of this service to yet
another userver, using an entry
in the the [SERVICES_EXEC] assignment file section, the request fails with this
error

<soapenv:Fault>
<faultcode>soapenv:Server</faultcode>
<faultstring>Activation error occurred</faultstring>

<faultactor>urn:uniface:applic:userver:doSoapRequest:URBPOLYnewReq</faultactor>
<detail>
<status>-180</status>
<description>Access denied</description>
</detail>
</soapenv:Fault>

This happens with G402, the patch which introduced the new functionaliy of
PUBLIC WEB and PUBLIC SOAP.
It works fine in G401 and earlier.
It also works fine if the targeted userver executes the request instead of
delegating it elsewhere.

The problem seems specific to SOAP, when you activate the service directly in
4GL, it has no problem
being redirected to another userver.