Traefik - Bad Gateway after login

Question

I have several containers (nextcloud, mariadb, vaultwarden...), including Traefik for a reverse proxy.

I use Traefik to access my NAS too, which is another device on my LAN (192.168.0.27). I want to use it even to access my router's interface (192.168.0.1).

It works fine for all the containers and the NAS but there is an error Bad Gateway when I try to log in to my router's interface : I can put my login and password in the fields but when I validate there is an error Bad Gateway.

docker-compose.yml:

version: '3.7'
services:
  traefik:
    container_name: traefik
    image: traefik:latest
    restart: unless-stopped
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
      - ./certs/:/letsencrypt/
      - ./conf/traefik.yml:/etc/traefik/traefik.yml:ro
      - ./dynamic/:/etc/traefik/config/:ro
      - ./logs/traefik.log:/var/log/traefik/logs/traefik.log
      - ./logs/traefik_access.log:/var/log/traefik/traefik_access.log
      - ./credentials/:/credentials/:ro
    networks:
      traefik_lan:
      wan:
      mariadb:
    ports:
      - '80:80'
      - '443:443'
    labels:
      traefik.enable: True
      traefik.docker.network: wan
      traefik.http.routers.traefik.middlewares: authentication@file,SecHeader@file
      traefik.http.routers.traefik.rule: Host(`traefik.mydomain.xyz`)
      traefik.http.routers.traefik.service: api@internal
      traefik.http.routers.traefik.tls: True
      traefik.http.routers.traefik.tls.certresolver: certbot
      providers.docker.network: wan
      traefik.http.routers.nas.entrypoints: web_secure
      traefik.http.routers.nas.rule: Host(`nas.mydomain.xyz`)
      traefik.http.routers.nas.service: nas@file
      traefik.http.routers.nas.tls: true
      traefik.http.routers.nas.tls.certresolver: certbot
      traefik.http.routers.box.entrypoints: web_secure
      traefik.http.routers.box.rule: Host(`box.mydomain.xyz`)
      traefik.http.routers.box.service: box@file
      traefik.http.routers.box.tls: true
      traefik.http.routers.box.tls.certresolver: certbot
networks:
  traefik_lan:
    external: True
  wan:
    external: True
  mariadb:
    driver: bridge
    external: True

traefik.yml:

global:
  sendAnonymousUsage: false

entryPoints:
  web:
    address: ':80'
    http:
      redirections:
        entryPoint:
          to: web_secure
  web_secure:
    address: ':443'
    http:
      middlewares:
        - SecHeader@file

api:
  dashboard: True
  insecure: False

log:
  filePath: /var/log/traefik/logs/traefik.log
  format: common
  level: INFO

accessLog:
  filePath: /var/log/traefik/traefik_access.log

providers:
  docker:
    exposedByDefault: False
  file:
    directory: /etc/traefik/config/

certificatesResolvers:
  certbot:
    acme:
      email: [email protected]
      keyType: 'RSA4096'
      storage: /letsencrypt/acme.json
      httpChallenge:
        entryPoint: web"

traefik.log (DEBUG):

time="2023-11-16T20:26:31Z" level=debug msg="http: TLS handshake error from 192.241.200.70:46852: tls: client offered only unsupported versions: [302 301]"
time="2023-11-16T20:26:41Z" level=debug msg="Request has been aborted [92.88.255.51:34812 - /menu/jquery.min.js]: net/http: abort Handler" middlewareName=traefik-internal-recovery middlewareType=Recovery
time="2023-11-16T20:26:45Z" level=debug msg="Request has been aborted [92.88.255.51:34812 - /menu/jquery.min.js]: net/http: abort Handler" middlewareName=traefik-internal-recovery middlewareType=Recovery
time="2023-11-16T20:26:52Z" level=debug msg="'502 Bad Gateway' caused by: read tcp 172.18.0.3:39218->192.168.0.1:80: read: connection reset by peer"

I tried to indicate network and port like said here: Traefik > "Bad gateway" (error 502) for some containers but the container Traefik doesn't work any more (the way isn't exactly the same as described in this link because I want to redirect to LAN and not to docker containers)

The conf is exactly the same for accessing my NAS and there is no problem with my NAS.