Two Docker Containers: Connection refused over websocket

Hi all - having a hard time figuring out a hard issue here. I’ve been trying to get one docker container to host a websocket server and other container to be a client to it. The problem is that no matter what settings I try (network: host or custom network) I always get the following error:

0 can not connect: dial tcp 172.29.0.3:8080: connect: connection refused

The ip address is coming from directly naming the service that hosts the websocket server in the code, so it’s not an issue of using localhost.

Here is my config file:

version: '3.5'

networks:
  proxynet:
    name: custom_network
    driver: bridge

services:
  testing_service:
    build:
      context: PATH
      dockerfile: build/testing_service.Dockerfile
    volumes:
      - PATH:/app

    networks:
      - proxynet

  student_server:
    build:
      context: PATH
      dockerfile: build/student_service.Dockerfile
    volumes:
      - PATH:/app
    networks:
      - proxynet
    ports:
        - "8080:80"

I am able to connect to the websocket server through my localhost and am able to ping the containers from within the containers - which confuses the issue a lot.