NC is running and extern rachable but nc-server says no internet connection

Hallo,
2 months ago I installed nc on debian 11 and docker. It was running great. Now I tried reinstall it (using same compose file) on new hardware and have a problem. Nextcloud ist running and it works. I can reach it from extern (I use mariadb, traefik and redis). But if I want to use the adminstration page, nc say that there is no active internet connection. I cannot install apps and so on. Dont find an error. The only difference is NC-Version (former was 25.0.2 and now it is 25.0.3 - but the older version is also not working).
I hope, someone can help me. Thanks.
(And sorry for my bad english).

Here is my docker compose file:
version: ‘3.7’
services:

Proxy für den externen Zugriff

traefik:
env_file:
- .env
# The official v2 Traefik docker image
image: traefik:${TRAEFIK_VERSION}
container_name: “traefik”
restart: unless-stopped
command:
- --global.checkNewVersion=true
- --global.sendAnonymousUsage=false
- --entrypoints.web.address=:80
- --entrypoints.websecure.address=:443
- --entrypoints.https.http.tls.options=tls-opts@file
- --api=true
- --api.dashboard=true
- --ping=true
- --log.level=${TRAEFIK_LOG_LEVEL}
- --log.filePath=/logs/traefik.log
- --accessLog.bufferingSize=100 # Configuring a buffer of 100 lines
- --accessLog.filters.statusCodes=204-299,400-499,500-599
- --providers.docker=true
- --providers.docker.exposedbydefault=false
- --providers.docker.network=nextcloud_web
- --providers.docker.swarmMode=false
# forward port 80 → 443
- --entrypoints.web.http.redirections.entryPoint.to=websecure
- --entrypoints.web.http.redirections.entryPoint.scheme=https
# cert resolver config
- --entrypoints.https.http.tls.certresolver=myresolver

- --certificatesResolvers.myresolver.acme.caServer=https://acme-staging-v02.api.letsencrypt.org/directory # LetsEncrypt Staging Server - uncomment when testing

  - --certificatesresolvers.myresolver.acme.email=${TRAEFIK_LE_CERT_MAILADRDRESS}"
  - --certificatesresolvers.myresolver.acme.storage=/acme.json
  - --certificatesresolvers.myresolver.acme.httpchallenge=true
  - --certificatesresolvers.myresolver.acme.httpchallenge.entrypoint=web
  - --certificatesresolvers.myresolver.acme.tlschallenge=true
  - --certificatesresolvers.myresolver.acme.dnschallenge=true
  - --certificatesresolvers.myresolver.acme.dnschallenge.provider=desec
  - --certificatesresolvers.myresolver.acme.dnschallenge.delayBeforeCheck=100
  - --certificatesresolvers.myresolver.acme.dnschallenge.resolvers=${TRAEFIK_DOMAIN_REGISTRAR_DNS},1.1.1.1:53,8.8.8.8:53
  - --entrypoints.websecure.http.tls.domains[0].main=${DOMAIN}
  - --entrypoints.websecure.http.tls.domains[0].sans=*.${DOMAIN}
ports:
   - "80:80"
   - "443:443"
volumes:
  - ./rules:/rules # file provider directory
  - /var/run/docker.sock:/var/run/docker.sock:ro # Use Docker Socket Proxy instead for improved security
  - ./acme/acme.json:/acme.json # cert location - you must create this emtpy file and change permissions to 600
  - ./logs:/logs # for fail2ban or crowdsec
  - ./shared:/shared
  - /etc/localtime:/etc/localtime:ro
labels:
  - traefik.enable=true
  - traefik.http.routers.api.rule=Host(`${TRAEFIK_HOST}.${DOMAIN}`)
  - traefik.http.routers.api.service=api@internal 
  - traefik.http.routers.api.middlewares=auth
  - traefik.http.middlewares.auth.basicauth.users=${BASIC_AUTH_USERS}:${BASIC_AUTH_HASH}
  - traefik.http.routers.api.entrypoints=websecure

- traefik.http.routers.api.tls.certresolver=myresolver ### auskommentieren nach erstem Lauf

  - "traefik.frontend.redirect.permanent: 'true'"   ### siehe Nextcloud-Doku (https://docs.nextcloud.com/server/25/admin_manual/configuration_server/reverse_proxy_configuration.html)
  - traefik.http.routers.api.tls=true
  - traefik.http.routers.api.tls.domains[0].main=${DOMAIN}
  - traefik.http.routers.api.tls.domains[0].sans=*.${DOMAIN}

  - traefik.http.middlewares.api.headers.stsSeconds=155520011
  - traefik.http.middlewares.api.headers.stsIncludeSubdomains=true
  - traefik.http.middlewares.api.headers.stsPreload=true

  - TZ=$TZ
  - HTPASSWD_FILE=./shared:/shared/.htpasswd # HTPASSWD_FILE can be whatever as it is not used/called anywhere.
  - DOMAINNAME_CLOUD_SERVER # Passing the domain name to traefik container to be able to use the variable in rules.
  - DESEC_TOKEN=$DESEC_TOKEN
networks:
  - "web"
  - "traefik-proxy"
healthcheck:
  test: ["CMD", "traefik", "healthcheck", "--ping"]
  interval: 5s
  retries: 3

nextcloud:
env_file:
- .env
image: nextcloud:${NEXTCLOUD_VERSION}
container_name: nextcloud
restart: always
volumes:
- ./cloud:/var/www/html
- ./cloud/apps:/var/www/html/apps
- ./cloud/config:/var/www/html/config
- ./cloud/db:/var/lib/mysql
- ./logs:/logs # for fail2ban or crowdsec
environment:
- MYSQL_DATABASE=${MYSQL_DATABASE}
- MYSQL_USER=${MYSQL_USER}
- MYSQL_PASSWORD=${MYSQL_PW}
- MYSQL_HOST=${MYSQL_HOST}

  - NEXTCLOUD_ADMIN_USER=${NEXTCLOUD_ADMIN_USER}
  - NEXTCLOUD_ADMIN_PASSWORD=${NEXTCLOUD_ADMIN_PW}
  - NEXTCLOUD_TRUSTED_DOMAINS='${NEXTCLOUD_HOST}.${DOMAIN}' '${DOMAIN}' 'localhost' '${NEXTCLOUD_HOST}.localhost' '192.168.32.0' '192.168.0.0' # nextcloud.mydomain.com
  - TRUSTED_PROXIES=172.21.0.2/16  ### Abfrage durch docker inspect traefik (IPAddress und IPPrefixLen von traefik_proxy)
  - OVERWRITEHOST=${NEXTCLOUD_HOST}.${DOMAIN}
  - OVERWRITEPROTOCOL=https
  - OVERWRITECLIURL=https://${NEXTCLOUD_HOST}.${DOMAIN}
  - REDIS_HOST=${REDIS_HOST}
  - REDIS_HOST_PASSWORD=${REDIS_PW}
  - DEFAULT_PHONE_REGION=DE
  - DEFAULT_LANGUAGE=de
  - DEFAULT_LOCALE=de_DE
depends_on:
  - nextcloud_db
  - redis
labels:
  - "traefik.enable=true"
  - "traefik.http.routers.nextcloud.rule=Host(`${NEXTCLOUD_HOST}.${DOMAIN}`)"
  - "traefik.http.routers.nextcloud.entrypoints=websecure"
  - "traefik.http.routers.nextcloud.tls.certresolver=myresolver"

  - "traefik.http.middlewares.nextcloud.headers.stsSeconds=155520011"
  - "traefik.http.middlewares.nextcloud.headers.stsIncludeSubdomains=true"
  - "traefik.http.middlewares.nextcloud.headers.stsPreload=true"
  - traefik.http.middlewares.nextcloud.headers.forceSTSHeader=true
  - "traefik.http.routers.nextcloud.middlewares=nextcloud,nextcloud_redirect"
  - "traefik.http.routers.nextcloud.tls=true"
  - "traefik.http.middlewares.nextcloud.headers.customFrameOptionsValue=ALLOW-FROM https://${NEXTCLOUD_HOST}.${DOMAIN}"
  - "traefik.http.middlewares.nextcloud.headers.contentSecurityPolicy=frame-ancestors 'self' ${NEXTCLOUD_HOST}.${DOMAIN} *.${NEXTCLOUD_HOST} ${DOMAIN}"
  - "traefik.http.middlewares.nextcloud.headers.customresponseheaders.X-Frame-Options=SAMEORIGIN"
  - "traefik.http.middlewares.nextcloud_redirect.redirectregex.permanent=true"
  - "traefik.http.middlewares.nextcloud_redirect.redirectregex.regex=https://(.*)/.well-known/(card|cal)dav"
  - "traefik.http.middlewares.nextcloud_redirect.redirectregex.replacement=https://$${1}/remote.php/dav/"

networks:
 - "web"

nextcloud_db:
env_file:
- .env
image: arm64v8/mariadb:${DB_VERSION}
container_name: nextcloud_db

command: --transaction-isolation=READ-COMMITTED --binlog-format=ROW --character_set_server=utf8mb4 --collation_server=utf8mb4_general_ci --skip-innodb-read-only-compressed --innodb_large_prefix=on --innodb_file_format=barracuda --i> command:

  - --transaction-isolation=READ-COMMITTED
  - --general-log
  - --log-bin=nextccloud_db
  - --binlog-format=ROW
  - --innodb-file-per-table=1
  - --skip-innodb-read-only-compressed
restart: always
volumes:
  - ./cloud/db:/var/lib/mysql
environment:
  - MYSQL_DATABASE=${MYSQL_DATABASE}
  - MYSQL_ROOT_PASSWORD=${MYSQL_ROOT_PW}
  - MYSQL_USER=${MYSQL_USER}
  - MYSQL_PASSWORD=${MYSQL_PW}
healthcheck:
  test: ["CMD", "mysqladmin", "ping", "--silent"]
networks:
 - "web"

redis:
env_file:
- .env
image: redis:${REDIS_VERSION}
container_name: redis
restart: unless-stopped
volumes:
- ./logs:/logs # for fail2ban or crowdsec

- ./cloud/redis-data:/var/lib/redis

  - ./cloud/redis_data:/data:rw
environment:
  - REDIS_PASSWORD=${REDIS_PW}
command: redis-server --requirepass "${REDIS_PW}"
healthcheck:
  test: ["CMD", "redis-cli", "ping"]
  interval: 1s
  timeout: 3s
  retries: 30
networks:
 - "web"

cron:
env_file:
- .env
image: nextcloud:${NEXTCLOUD_VERSION}
restart: always
volumes:
- ./cloud:/var/www/html
- ./cloud/apps:/var/www/html/apps
- ./cloud/config:/var/www/html/config
- ./cloud/db:/var/lib/mysql
entrypoint: /cron.sh
depends_on:
- nextcloud_db
- redis
networks:
- “web”

volumes:
redis_data:
nextcloud_db:
cloud:

networks:
web:
external: false
traefik-proxy:
external: true