I am trying to set the Plain Text of an artifact in RRC using the OSLC rest API and the creation does not set the plain text at all.

Following is the code snippet which I am trying to use to set the plain text in RRC rich text editor

        String title = "MyDocument7";
        String description = "This is a test document created";
        //Note: primary text must be in xhtml compliant format
        String primaryText = "<div xmlns=\"http://www.w3.org/1999/xhtml\" >Test Document</div>";
                           
        //Create a requirement request - Note the URL is "" because the requirement is not yet created
        RequirementRequest req = new RequirementRequest(server, "", shapeURL);
        req.setDcTitle(title);
        req.setDcDescription(description);
       
        //Add any internal properties to request by getting property URI from shape
        String primaryTextPropURI = findPropertyByTitle(doc, "Primary Text");
        System.out.println("printing the property URI ... "+primaryTextPropURI);
        req.addRMLiteralProperty(primaryTextPropURI, primaryText);
        //System.out.println("getting the content based on URI "+req.getPrimaryText(primaryTextPropURI));

Now the artifact does get created correctly but the primaryTextPropURI does not have the correct value. The return from the method findPropertyByTitle is null. The method conatins the following snippet:

protected String findPropertyByTitle(Document doc, String title) throws Exception {
        String propertyDefinition = "//oslc:Property[oslc:name=\"" + title +"\"]/oslc:propertyDefinition/@rdf:resource";
        XPath xpathNamespace = getXpathNamespace();
        Node node = (Node) xpathNamespace.evaluate(propertyDefinition, doc, XPathConstants.NODE);
        if(node != null){
            return node.getTextContent();
        }
        return null;
    }

Can someone help understand why this does not work.