Traefik hiccup - why can't my containers find the network I defined for them in docker-compose?

Traefik Traefik v2
1

I've seen a couple of threads on similar issues, but their solutions haven't resolved my issue. I run Traefik with docker-scoket-proxy and it seemed like everything was great - I can access containers externally after authentication, dashboard looks good, etc, but in checking my logs I found this for each of my containers behind Docker:

level=warning msg="Could not find network named 'default' for container '/portainer'! Maybe you're missing the project's prefix in the label? Defaulting to first available network."

I don't use a static config file or anything else that I can see that would complicate this. Here is my docker-compose.yml contents:

version: "3.7"

########################### NETWORKS
networks:
  t2_proxy:
    external:
      name: t2_proxy
  default:
    driver: bridge

########################### SERVICES
services:

########################## SOCKETPROXY
  dockerproxy:
    container_name: dockerproxy
    restart: always
    image: tecnativa/docker-socket-proxy
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock:z
    environment:
      CONTAINERS: 1
    networks:
      - t2_proxy

############################# FRONTENDS

  traefik:
    container_name: traefik
    image: traefik:chevrotin
    depends_on:
      - dockerproxy
    restart: always
    command: # CLI arguments
      - --global.checkNewVersion=true
      - --global.sendAnonymousUsage=false
      - --entryPoints.http.address=:80
      - --entrypoints.https.forwardedHeaders.trustedIPs=173.245.48.0/20,103.21.244.0/22,103.22.200.0/22,103.31.4.0/22,141.101.64.0/18,108.162.192.0/18,190.93.240.0/20,188.114.96.0/20,197.234.240.0/22,198.41.128.0/17,162.158.0.0/15,104.16.0.0/12,172.64.0.0/13,131.0.72.0/22
      - --entryPoints.https.address=:443
      - --entryPoints.traefik.address=:8080
      - --api=true
      - --log=true
      - --log.level=INFO # (Default: error) DEBUG, INFO, WARN, ERROR, FATAL, PANIC
      - --accessLog=true
      - --accessLog.filePath=/var/log/docker/traefik.log
      - --accessLog.bufferingSize=100 # Configuring a buffer of 100 lines
      - --accessLog.filters.statusCodes=400-499
      - --providers.docker=true
      - --providers.docker.defaultrule=Host(`{{ index .Labels "com.docker.compose.service" }}.$DOMAINNAME`)
      - --providers.docker.exposedByDefault=false
      - --providers.docker.network=default     
      - --providers.docker.endpoint=tcp://dockerproxy:2375      
      - --providers.docker.swarmMode=false
      - --providers.file.directory=/rules # Load dynamic configuration from one or more .toml or .yml files in a directory.
      - --providers.file.watch=true # Only works on top level files in the rules folder
      - --certificatesResolvers.dns-cloudflare.acme.caServer=https://acme-staging-v02.api.letsencrypt.org/directory # uncomment when testing
      - --certificatesResolvers.dns-cloudflare.acme.email=$CLOUDFLARE_EMAIL
      - --certificatesResolvers.dns-cloudflare.acme.storage=/acme.json
      - --certificatesResolvers.dns-cloudflare.acme.dnsChallenge.provider=cloudflare
    networks:
      t2_proxy:
        ipv4_address: 192.168.180.254
      default:
    ports:
      # https://www.reddit.com/r/docker/comments/c1wrep/traefik_reverse_proxy_question_docker_overlay/
      - target: 80
        published: 80
        protocol: tcp
        mode: host
      - target: 443
        published: 443
        protocol: tcp
        mode: host
      - target: 8080
        published: 8080
        protocol: tcp
        mode: host
    volumes:
      - $USERDIR/docker/traefik2/rules:/rules # file provider directory
      - $USERDIR/docker/traefik2/acme/acme.json:/acme.json # cert location - you must touch this file and change permissions to 600
      - $USERDIR/docker/traefik2/traefik.log:/var/log/docker/traefik.log # for fail2ban - make sure to touch file before starting container
      - ${USERDIR}/docker/shared:/shared
    environment:
      - CF_API_EMAIL=$CLOUDFLARE_EMAIL
      - CF_API_KEY=$CLOUDFLARE_API_KEY
    labels:
      - "traefik.enable=true"
      - "traefik.http.routers.http-catchall.entrypoints=http"
      - "traefik.http.routers.http-catchall.rule=HostRegexp(`{host:.+}`)"
      - "traefik.http.routers.http-catchall.middlewares=redirect-to-https"
      - "traefik.http.middlewares.redirect-to-https.redirectscheme.scheme=https"
      - "traefik.http.routers.traefik-rtr.entrypoints=https"
      - "traefik.http.routers.traefik-rtr.tls=true"
      - "traefik.http.routers.traefik-rtr.tls.domains[0].main=$DOMAINNAME"
      - "traefik.http.routers.traefik-rtr.tls.domains[0].sans=*.$DOMAINNAME"
      - "traefik.http.routers.traefik-rtr.middlewares=traefik-headers,rate-limit@file,oauth@file" #basic-auth@file
      - "traefik.http.middlewares.traefik-headers.headers.accesscontrolallowmethods=GET, OPTIONS, PUT"
      - "traefik.http.middlewares.traefik-headers.headers.accessControlAllowOriginList=https://$DOMAINNAME"
      - "traefik.http.middlewares.traefik-headers.headers.accesscontrolmaxage=100"
      - "traefik.http.middlewares.traefik-headers.headers.addvaryheader=true"
      - "traefik.http.middlewares.traefik-headers.headers.allowedhosts=traefik.$DOMAINNAME"
      - "traefik.http.middlewares.traefik-headers.headers.hostsproxyheaders=X-Forwarded-Host"
      - "traefik.http.middlewares.traefik-headers.headers.sslredirect=true"
      - "traefik.http.middlewares.traefik-headers.headers.sslhost=traefik.$DOMAINNAME"
      - "traefik.http.middlewares.traefik-headers.headers.sslforcehost=true"
      - "traefik.http.middlewares.traefik-headers.headers.sslproxyheaders.X-Forwarded-Proto=https"
      - "traefik.http.middlewares.traefik-headers.headers.stsseconds=63072000"
      - "traefik.http.middlewares.traefik-headers.headers.stsincludesubdomains=true"
      - "traefik.http.middlewares.traefik-headers.headers.stspreload=true"
      - "traefik.http.middlewares.traefik-headers.headers.forcestsheader=true"
      - "traefik.http.middlewares.traefik-headers.headers.framedeny=true"
      - "traefik.http.middlewares.traefik-headers.headers.customFrameOptionsValue='allow-from https:$DOMAINNAME'"
      - "traefik.http.middlewares.traefik-headers.headers.contenttypenosniff=true"
      - "traefik.http.middlewares.traefik-headers.headers.browserxssfilter=true"
      - "traefik.http.middlewares.traefik-headers.headers.referrerpolicy=same-origin"
      - "traefik.http.middlewares.traefik-headers.headers.featurepolicy=camera 'none'; geolocation 'none'; microphone 'none'; payment 'none'; usb 'none'; vr 'none';"
      - "traefik.http.middlewares.traefik-headers.headers.customresponseheaders.X-Robots-Tag=none,noarchive,nosnippet,notranslate,noimageindex,"
      - "traefik.http.routers.traefik-rtr.service=api@internal"

#[SNIPPED AUTH CONTAINER STUFF]

  portainer:
    container_name: portainer
    image: portainer/portainer:latest
    restart: always
    command: -H unix:///var/run/docker.sock
    networks:
      - default
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock:ro
      - $USERDIR/docker/portainer/data:/data # Change to local directory if you want to save/transfer config locally
    environment:
      - TZ=$TZ
    labels:
      - "traefik.enable=true"
      - "traefik.http.routers.portainer-rtr.entrypoints=https"
      - "traefik.http.routers.portainer-rtr.rule=Host(`portainer.$DOMAINNAME`)"
      - "traefik.http.routers.portainer-rtr.tls=true"
      - "traefik.http.routers.portainer-rtr.tls.certresolver=dns-cloudflare"
      - "traefik.http.routers.portainer-rtr.middlewares=secure-chain@file"
      - "traefik.http.routers.portainer-rtr.service=portainer-svc"
      - "traefik.http.services.portainer-svc.loadbalancer.server.port=9000"

I thought it was maybe a complication with the name "default", so I tried renaming it to "proxynet", but that didn't work. I think MAYBE it has to do the the fact that, as this is from docker-compose and under the /docker directory that the actual net created is docker_default or docker_proxynet, but even if I try to edit those in this file I end up with something like docker_docker_proxynet, so I must be doing something really basic wrong here - I just can't figure out what that is.