npm run serve increases port instead of reusing :8080

I have a problem with npm run serve because it does not use port 8080, instead after every npm run serve the port is increased so now I'm on 8091.

But I use django-webpack-loader which needs to use 8080.

(feedbot) milano@milano-desktop:~/PycharmProjects/feedbot/frontend$ npm run serve 

> frontend@0.1.0 serve /home/milano/PycharmProjects/feedbot/frontend
> vue-cli-service serve

 INFO  Starting development server...
98% after emitting CopyPlugin

 DONE  Compiled successfully in 1125ms     


  App running at:
  - Local:   http://localhost:8091/ <<<<<< HERE YOU CAN SEE THE PORT
  - Network: http://0.0.0.0:8080/


                                                                10:37:55 PM

I use this in my template:

 <div id="app">
            <app></app>
 </div>
 {% render_bundle 'index' %}

I can see in inspect that render_bundle renders wrong url:

http://127.0.0.1:8080/index.js

How do I make it work? The npm increases port instead of reusing 8080.

So either I make django-webpack-loader to somehow recognize which port is in use or npm to reuse 8080.

EDIT

sudo netstat -ap | grep :8080

returns nothing so I don't understand why the server is not using it