Switch router/middleware config from docker labels to file does not work

Traefik Traefik v3 (latest)
,
1

Hi,
I run Traefik on AWS ECS with discovery, working good so far.
Now I want to migrate middleware and router settings from docker labels to config file, but I cant get it working (http 404).
I also tried with exposedByDefault=true and without traefik.enable.

What am I missing?

Working:

#traefik.yaml
api:
  dashboard: true
  insecure: false
entryPoints:
  web:
    address: ":80"
log:
  format: common
  level: DEBUG
  noColor: true
ping: {}
providers:
  ecs:
    clusters:
      - arn:aws:ecs:eu-central-1:xxxx
    exposedByDefault: false
    region: eu-central-1

#Docker Labels:
    "traefik.enable": "true",
    "traefik.http.middlewares.auth.basicauth.users": "test:xxx",
    "traefik.http.routers.test.entrypoints": "web",
    "traefik.http.routers.test.middlewares": "auth",
    "traefik.http.routers.test.service": "my-test-service-test@ecs",
    "traefik.http.routers.test.rule": "Host(`test.mydomain.net`)",

Now Working

#traefik.yaml
api:
  dashboard: true
  insecure: false
entryPoints:
  web:
    address: ":80"
http:
  routers:
    test:
      entryPoints:
        - web
      middlewares:
       - auth   # (also tried auth@file)
      rule: "Host(`test.mydomain.net`)"
      service: my-test-service-test@ecs
  middlewares:
    auth:
      basicAuth:
        users:
          - "test:xxx"
log:
  format: common
  level: DEBUG
  noColor: true
ping: {}
providers:
  ecs:
    clusters:
      - arn:aws:ecs:eu-central-1:xxxx
    exposedByDefault: false
    region: eu-central-1

#Docker Labels:
    "traefik.enable": "true"