Non accessible node.js server

  hosting, node.js, php, server, symfony

I am developing a web application on my windows machine, using PhpStorm and Symfony 5 as a framework.

My application contains a video chat feature.
For that i am using node.js and peer.js to ensure the real time communication.

So far and, LOCALLY (localhost:8000 for the Symfony app, and localhost:3000), all working good, users connect to the chat room, make their video call and then leave the chat room.

Assuming that : x.x.x.x is the ip address of the windows machine hosting the app,
8000 is the port on which Symfony serves and 3000 is the port on which Node serves.

The problem is when i connect to my machine EXTERNALLY (using an other machine), the Symfony app is accessible (x.x.x.x:8000), but the node app is not (x.x.x.x:3000).

On google chrome i get this :
"This site can’t provide a secure connection
x.x.x.x sent an invalid response.

I think the problem is linked to ssl and certification.
My node app is not using any keys or certifications.

Any help ?

Source: Symfony Questions