Traefik with OwnCloud - Bad Gateway Error

Question

I have setup a traefik container which is providing the proxy services for my owncloud docker container. However, when I start my owncloud container I get 'Bad Gateway' error when I browse to http://example.xlxl.co.uk. The http to https redirections is working fine, so is the Lets Encrypt SSL integrtion. In addition to this if i go to http://traefik.xlxl.co.uk, I can also see the traefik dashboard, however when i go to the URL for my owncloud container (http://example.xlxl.co.uk) I get 'Bad Gateway'....I have tried many different things now, exposing ports within the owncloud docker-compose file etc. but to no avail...and now completely lost. The traefik container is setup with the following configuration for docker-compose.yml

---

version: '2'

services:
  proxy:
    # You might want to use a proper version
    image: traefik
    command: --configFile=/traefik.toml
    restart: unless-stopped
    # Here's the network we created:
    networks:
      - web
    # The traefik entryPoints
    ports:
      - "80:80"
      - "443:443"
      - "8080:8080"
    labels:
      - "traefik.enable=true"
      - "traefik.backend=traefik"
      - "traefik.frontend.rule=Host:traefik.xlxl.co.uk"
      # Traefik will proxy to its own GUI.
      - "traefik.port=8080"
      - "traefik.docker.network=web"
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
      - /opt/traefik/traefik.toml:/traefik.toml
      - /opt/traefik/acme.json:/acme.json

networks:
  web:
    external: true

---

And the traefik.toml is as below

---

logLevel = "DEBUG"
defaultEntryPoints = ["https","http"]

[entryPoints]
  [entryPoints.http]
  address = ":80"
    [entryPoints.http.redirect]
    entryPoint = "https"
  [entryPoints.https]
  address = ":443"
  [entryPoints.https.tls]
  minVersion = "VersionTLS12"

[docker]
   endpoint = "unix:///var/run/docker.sock"
   domain = "xlxl.co.uk"
   watch = true
   exposedbydefault = false
   network = "web"

[acme]
    email = "[e-mail]"
    storage = "/acme.json"
    entryPoint = "https"
    [acme.tlsChallenge]
    onDemand = true
    onHostRule = true
    acmeLogging = true
    caServer = "https://acme-staging.api.letsencrypt.org/directory"
    [[acme.domains]]
      main = "xlxl.co.uk"
      sans = ["example.xlxl.co.uk"]

# enable web configuration backend.
[api]
  entryPoint = "traefik"
  dashboard = true
  address = ":8080"

---

And the the owncloud docker container's docker-compose.yml configuration as below:

---

version: '2.1'
services:
    owncloud:
        image: 'owncloud/server:${OWNCLOUD_VERSION}'
        restart: always
        depends_on:
            - db
            - redis
        environment:
            - 'OWNCLOUD_DOMAIN=${OWNCLOUD_DOMAIN}'
            - OWNCLOUD_DB_TYPE=mysql
            - OWNCLOUD_DB_NAME=owncloud
            - OWNCLOUD_DB_USERNAME=owncloud
            - OWNCLOUD_DB_PASSWORD=owncloud
            - OWNCLOUD_DB_HOST=db
            - 'OWNCLOUD_ADMIN_USERNAME=${ADMIN_USERNAME}'
            - 'OWNCLOUD_ADMIN_PASSWORD=${ADMIN_PASSWORD}'
            - OWNCLOUD_MYSQL_UTF8MB4=true
            - OWNCLOUD_REDIS_ENABLED=true
            - OWNCLOUD_REDIS_HOST=redis
        networks:
            - web
            - internal
        healthcheck:
            test: [CMD, /usr/bin/healthcheck]
            interval: 30s
            timeout: 10s
            retries: 5
        volumes:
            - '/opt/ownCloud/data:/var/www/html/data'
            - '/opt/ownCloud/config:/var/www/html/config'
        labels:
            -  traefik.enable=true
            -  traefik.frontend.rule=Host:example.xlxl.co.uk
            -  traefik.port=80
            -  traefik.docker.network=web
    db:
        image: 'webhippie/mariadb:latest'
        restart: always
        environment:
            - MARIADB_ROOT_PASSWORD=owncloud
            - MARIADB_USERNAME=owncloud
            - MARIADB_PASSWORD=owncloud
            - MARIADB_DATABASE=owncloud
            - MARIADB_MAX_ALLOWED_PACKET=128M
            - MARIADB_INNODB_LOG_FILE_SIZE=64M
        networks:
            - internal
        healthcheck:
            test: [CMD, /usr/bin/healthcheck]
            interval: 30s
            timeout: 10s
            retries: 5
        volumes:
            - '/opt/ownCloud/mysql:/var/lib/mysql'
            - '/opt/ownCloud/mysql/backup:/var/lib/backup'
        labels:
            - traefik.enable=false
    redis:
        image: 'webhippie/redis:latest'
        restart: always
        environment:
            - REDIS_DATABASES=1
        networks:
            - internal
        healthcheck:
            test: [CMD, /usr/bin/healthcheck]
            interval: 30s
            timeout: 10s
            retries: 5
        volumes:
            - '/opt/ownCloud/redis:/var/lib/redis'
        labels:
            - traefik.enable=false
networks:
   web:
     external: true
   internal: