sorry for the late response and thank you for helping me.
Visual Studio's debug is disabled as soon as you open the Chrome inspector but anyway I checked the token and apparently it was always the same.
I found out that the problem was that Visual Studio uses his own version of Node.js and there was a compatibility problem. I wrongly assumed it was ok since most of the webservices worked. Apparently you can set it to use the version you need but I decided to switch to Sublime Text and better follow the moodle mobile development guide with a different workflow (and Node.js 0.12.7 ).
Thanks again and best regards,