Compose: nginx can't connect to docker embedded dns

[yarkaktus]

I'm trying to make an application with about the following functionality:

when the user enters 1234.my.domain.com, he should see the small django-application response that is in the container with port 1234.

On my server, I have nginx(on the server, not in container!) with the configuration for my task:

server {
    listen 80 default_server;
    listen [::]:80 default_server ipv6only=on;

    # This captures the subdomain (if digits) as the $backport variable
    server_name ~^(?P<backport>[0-9]+)\.my\.domain\.com$;

    location / {
        resolver 127.0.0.11 ipv6=off;

        if ($backport) {
                proxy_pass http://localhost:$backport;
        }
    }
}

and docker-compose.yml

version: '3'

services:
  db:
    image: postgres
  web:
    build: .
    command: python3.6 manage.py runserver 0.0.0.0:8080
    container_name: "task_${TASK_ID}"
    volumes:
      - .:/code
    ports:
      - "${TASK_ID}:8080"
    depends_on:
      - db

When I write docker-compose up, everything runs fine and when i write curl localhost:1234, i see django hello-world html code.
But when I type in the browser 1234.my.domain.com, I get 502 Bad Gateway.
In nginx error log i see

recv() failed (111: Connection refused) while resolving, resolver: 127.0.0.11:53

I googled a lot, but I did not find a solution to the problem. Maybe I'm missing something, but for me it's very strange that nginx can not connect to docker dns. It looks like a docker problem

Context information (for bug reports)

Output of "docker-compose version"

docker-compose version 1.21.0, build 5920eb0
docker-py version: 3.2.1
CPython version: 3.6.5
OpenSSL version: OpenSSL 1.0.1t  3 May 2016

Output of "docker version"

Client:
 Version:   17.12.1-ce
 API version:   1.35
 Go version:    go1.9.4
 Git commit:    7390fc6
 Built: Tue Feb 27 22:17:56 2018
 OS/Arch:   linux/amd64

Server:
 Engine:
  Version:  17.12.1-ce
  API version:  1.35 (minimum version 1.12)
  Go version:   go1.9.4
  Git commit:   7390fc6
  Built:    Tue Feb 27 22:16:28 2018
  OS/Arch:  linux/amd64
  Experimental: false

[shin-]

Please use the forums for support.

[Blasterdick]

@yarkaktus Have you been able to solve the issue? If so, then how? Facing the same problem in GKE kubernetes cluster. Thank you for any kind of help.