XPath encoding

Hello,

we are retrieving data from an API as JSON file.
For this we get an http response which we parse as XML with HtmlParser node.
To get the content in the body we use the XPath node.
It seems that some characters are not handled correctly. the « is transformed to "\".

The content is basicly something like

<?xml version="1.0" encoding="UTF-8"?>
<html xmlns="http://www.w3.org/1999/xhtml">
    <head>
    </head>
       <body>text «special text» text</body>
    </html>
    
With XPath node I receive:

    <body>text \nspecial text\n text</body>
    
Seems to be encoding, but I could not figure out where I can influence.
The xml setting it UTF-8

Problem is that the text in the body is a json result. Since the coding is not correct, we can not convert it with String to JSON.
Error message is: Unexpected character ('N' (code 78)): was expecting comma to separate OBJECT entries
 at [Source: java.io.StringReader@789f3530; line: 1, column: 802972]
 
I am happy if you can give us any hint.

Thanks

Bernd