Hi @Barder ,
Can you try adding "webSocket enabled=false" in your web.config. it may look confusing but this web.config setting turns off the IIS WebSockets support module (iiswsock.dll) since it isn’t needed by node.js. Nodej.js on IIS includes its own low-level implementation of WebSockets, which is why the IIS support module needs to be explicitly turned off.
Hope that helps. please let us know if you have further questions.
Thanks,
Grace