Docker – Can't access container exposed port

I have a problem with accessing an angular application deployed within a container.
I have exposed the port in my dockerfile, mapped the port in the docker-compose file but I still can’t access from my web browser (Mozilla).

I can’t find any error message that could guide me.

Can someone check out my files and tells me if there is a problem that I haven’t seen ?

docker-compose.yaml

version: '3'
services:
  frontend:
    build:
      context: .
      dockerfile: srcs/frontend/Dockerfile
    ports:
      - 4200:4200
    volumes:
      - frontend_data:/usr/src/app
    depends_on:
      - backend
    networks:
      - mynetwork
  backend:
    build:
      context: .
      dockerfile: srcs/backend/Dockerfile
    ports:
      - 3000:3000
    volumes:
      - backend_data:/usr/src/app
    depends_on:
      - database
    networks:
      - mynetwork
  database:
    image: mysql:latest
    environment:
      - MYSQL_ROOT_PASSWORD=your_root_password
      - MYSQL_DATABASE=your_database_name
      - MYSQL_USER=your_database_user
      - MYSQL_PASSWORD=your_database_password
    volumes:
      - ./mysql_data:/var/lib/mysql
    networks:
      - mynetwork

networks:
  mynetwork:
    driver: bridge

volumes:
  mysql_data:
  backend_data:
    driver: local
  frontend_data:
    driver: local

Frontend Dockerfile

FROM node:19-alpine

WORKDIR /usr/src/app

RUN npm install -g npm

COPY ./srcs/frontend .

RUN chmod +x /usr/src/app/entrypoint.sh

EXPOSE 4200


ENTRYPOINT [ "/usr/src/app/entrypoint.sh" ]

My entrypoint only contains

#!/bin/sh

npm install && npm run start

When I try to access 127.0.0.1:4200 from my web browser, I have the following error :

The connection was reset

The connection to the server was reset while the page was loading.

Is there something I missed ?

EDIT :
I have to add that I can’t access to the exposed port even if I only deploy the front-end container. And that I can access the app if I deploy it without contenerisation. So the problem is likely coming from my frontend Dockerfile

EDIT 2 :
I can ping the container from another container but not from my host.

Thanks in advance