XMLport- Different behavior in 2013R2 and 2015

ottobe

I am using an XMLport to generate an XML document to send to a Web Service.
The first line in the port is a text element: <soapenv:Envelope>
The intention is to create this line in the XML file:

-<soapenv:Envelope xmlns:web="http://ww... etc

This works fine in 2013R2, but in 2015 the first soapenv: is removed whatever I do, and the resulting XML doc line becomes:

-<Envelope xmlns="soapenv" xmlns:web="http://www.we... etc

This givers a 500- internal server error when sent to webservice.

Any ideas?