traefik: High CPU usage on traefik v2 compared to v1

version: '3.3'

services:

  traefik:
    image: traefik:2.1
    ports:
      - 80:80
      - 443:443
      - 8080:8080
    deploy:
      labels:
        - traefik.enable=true
        - traefik.docker.network=traefik-public
        - traefik.constraint-label=traefik-public
        - traefik.http.routers.traefik-public-http.entrypoints=http
        - traefik.http.routers.traefik-public-http.rule=Host(`api.example.com`)
        - traefik.http.routers.traefik-public-https.tls.certresolver=le
        - traefik.http.services.traefik-public.loadbalancer.server.port=80
      resources:
        limits:
          cpus: '0.1'
          memory: 128M
        reservations:
          cpus: '0.1'
          memory: 128M
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
    command:
      - --providers.docker
      - --providers.docker.swarmMode=true
      - --providers.docker.exposedbydefault=false
      - --providers.docker.endpoint=unix:///var/run/docker.sock
      - --certificatesresolvers.le.acme.caserver=https://acme-staging-v02.api.letsencrypt.org/directory
      - --certificatesresolvers.le.acme.email=email@email.com
      - --certificatesresolvers.le.acme.storage=/acme.json
      - --certificatesresolvers.le.acme.tlschallenge=true
      - --api.insecure=true
      - --api.dashboard=true
      - --accesslog
      - --log.level=debug
    networks:
      - traefik-public

volumes:
  traefik-public-certificates:

networks:
  traefik-public:
    external: true

version: "3.7"

services:

  whoami:
    image: containous/whoami
    networks:
      - traefik-public
      - default    
    deploy:
      labels:
        - traefik.enable=true
        - traefik.docker.network=traefik-public
        - traefik.http.routers.whoami.rule=Host(`api.example.com`) && Path(`/whoami`)
        - traefik.http.services.whoami.loadbalancer.server.port=5555

  flask:
    image: example/example
    restart: always
    networks:
      - traefik-public
      - default    
    environment:
      FLASK_DEBUG: 1
    env_file:
      - .env
    ports:
      - 3333:8080      
    deploy:
      labels:
        - traefik.enable=true
        - traefik.docker.network=traefik-public
        - traefik.http.routers.flask.rule=Host(`api.example.com`)
        - traefik.http.services.flask.loadbalancer.server.port=3333

  flower:  
    image: mher/flower
    networks:
      - traefik-public
      - default
    env_file:
      - .env    
    ports:  
      - 8888:8888 
    deploy:
      labels:
        - traefik.enable=true
        - traefik.docker.network=traefik-public
        - traefik.http.routers.flower.rule=Host(`api.example.com`) && Path(`/flower`)
        - traefik.http.services.flower.loadbalancer.server.port=8888

traefik_traefik.1.wivss1yy13gp@ds1
time="2021-01-21T01:27:09Z"
level=debug
msg="vulcand/oxy/roundrobin/rr: Forwarding this request to URL"
ForwardURL="http://10.0.1.5:80"
Request="
{
    "Method":"GET\",\"URL\":
        {
            \"Scheme\":\"\",\"Opaque\":\"\",
            \"User\":null,
            \"Host\":\"\",
            \"Path\":\"/flower/\",
            \"RawPath\":\"\",
            \"ForceQuery\":false,
            \"RawQuery\":\"\",
            \"Fragment\":\"\"
        },
    \"Proto\":\"HTTP/1.1\",
    \"ProtoMajor\":1,
    \"ProtoMinor\":1,
    \"Header\":
        {
            \"Accept\":
                [
                    \"text/html,
                    application/xhtml+xml,
                    application/xml;q=0.9,
                    image/avif,
                    image/webp,
                    image/apng,
                    */*;q=0.8,
                    application/signed-exchange;
                    v=b3;q=0.9\"
                ],
            \"Accept-Encoding\": [ \"gzip, deflate\"],
            \"Accept-Language\":  [ \"en-US,en;q=0.9\"],
            \"Sec-Gpc\":[\"1\"],
            \"Upgrade-Insecure-Requests\":[\"1\"],
            \"User-Agent\":[\"Mozilla/5.0(Macintosh; Intel Mac OS X 10_13_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.96 Safari/537.36\"],
            \"X-Forwarded-Host\":[\"api.example.com\"],
            \"X-Forwarded-Port\":[\"80\"],
            \"X-Forwarded-Proto\":[\"http\"],
            \"X-Forwarded-Server\":[\"1f31b0bc2622\"],
            \"X-Real-Ip\":[\"10.0.1.5\"]},
            \"ContentLength\":0,
            \"TransferEncoding\":null,
            \"Host\":\"api.example.com\",
            \"Form\":null,
            \"PostForm\":null,
            \"MultipartForm\":null,
            \"Trailer\":null,
            \"RemoteAddr\":\"10.0.1.5:34164\",
            \"RequestURI\":\"/flower/\",
            \"TLS\":null
        }"
}