Traefik v3.1 websocket connection works in Firefox, but not in Chrome

[raz1]

Hi. I have a traefik v3.1 configured on a server with multiple services. I just migrated all the configuration files from v2 version to v3.
The websocket service is working flawlessly on Firefox as you can see here:

but it's not working properly on Chrome/Brave (Version 1.68.128 Chromium: 127.0.6533.73 (Official Build) (arm64)):

Anyways from time to time (after many refreshes?) it's working even on Chrome but for a very short period of time. I don't know where can be the related issue. I need some help please. Here is my configuration files:

docker-compose.yml

version: "3.9"

services:

    nginx:
        image: nginx:1.17.6-alpine
        container_name: "${PROJECT_NAME}_nginx"
        restart: unless-stopped
        volumes:
            - ./:/var/html
            - ".docker/prod/nginx/nginx.conf:/etc/nginx/nginx.conf"
            - ".docker/prod/nginx/conf.d/:/etc/nginx/conf.d/"
            - ".docker/prod/nginx/server-opts.d/:/etc/nginx/server-opts.d/"
        networks:
            - mynetwork

    soketi:
        image: 'quay.io/soketi/soketi:latest-16-alpine'
        container_name: "${PROJECT_NAME}_soketi"
        restart: unless-stopped
        environment:
            SOKETI_DEBUG: 0
            SOKETI_METRICS_ENABLED: 1
            SOKETI_METRICS_SERVER_PORT: 9601
        command: soketi start --config=/config/config.json
        volumes:
            - .docker/prod/soketi/:/config
        networks:
            - mynetwork

    traefik:
        image: "traefik:v3.1"
        container_name: "traefik"
        restart: unless-stopped
        ports:
            - "80:80"
            - "443:443"
        environment:
            - "APP_DOMAIN=${APP_DOMAIN}"
            - "CF_API_EMAIL=${CF_API_EMAIL}"
            - "CF_DNS_API_TOKEN=${CF_DNS_API_TOKEN}"
            - "TZ=Europe/Bucharest"
        volumes:
            - "./.docker/prod/traefik:/etc/traefik/"
            - "./letsencrypt:/letsencrypt"
            - "/var/run/docker.sock:/var/run/docker.sock:ro"
        networks:
            - mynetwork

networks:
    mynetwork:
        name: "${PROJECT_NAME}_network"
        driver: bridge

traefik.yml

global:
  checkNewVersion: true

log:
  level: INFO

providers:
  providersThrottleDuration: 2s
  file:
    filename: /etc/traefik/fileConfig.yml
    watch: true
  docker:
    exposedByDefault: false
    watch: true

entrypoints:
  web:
    address: :80
    forwardedHeaders:
      trustedIPs:
        - 127.0.0.1/32
        - 172.20.0.0/24
        - 103.21.244.0/22
        - 103.22.200.0/22
        - 103.31.4.0/22
        - 104.16.0.0/13
        - 104.24.0.0/14
        - 108.162.192.0/18
        - 131.0.72.0/22
        - 141.101.64.0/18
        - 162.158.0.0/15
        - 172.64.0.0/13
        - 173.245.48.0/20
        - 188.114.96.0/20
        - 190.93.240.0/20
        - 197.234.240.0/22
        - 198.41.128.0/17
        - 2400:cb00::/32
        - 2606:4700::/32
        - 2803:f800::/32
        - 2405:b500::/32
        - 2405:8100::/32
        - 2a06:98c0::/29
        - 2c0f:f248::/32
    http:
      redirections:
        entryPoint:
          to: websecure
          scheme: https
          permanent: true
  websecure:
    address: :443
    http:
      tls:
        certResolver: myresolver
        domains:
          main: "${APP_DOMAIN}"
          sans:
            - "*.${APP_DOMAIN}"

certificatesResolvers:
  myresolver:
    acme:
      dnsChallenge:
        provider: cloudflare
        delayBeforeCheck: 10
      email: user@example.com
      storage: /letsencrypt/acme.json

api:
  dashboard: true
  insecure: false

fileConfig.yml

# Dynamic configuration
tls:
  options:
    default:
      sniStrict: true

http:
  routers:

    nginx:
      entryPoints:
        - websecure
      rule: "Host(`{{env "APP_DOMAIN"}}`) || HostRegexp(`.+.{{env "APP_DOMAIN"}}`)"
      service: nginx
      tls:
        certResolver: myresolver
      priority: 10

    soketi:
      entryPoints:
        - websecure
      rule: Host(`events.{{env "APP_DOMAIN"}}`)
      service: soketi
      tls:
        certResolver: myresolver
      priority: 100

    traefik-dashboard:
      entryPoints:
        - websecure
      rule: Host(`traefik.{{env "APP_DOMAIN"}}`)
      service: api@internal
      tls:
        certResolver: myresolver
      priority: 100
      middlewares:
        - traefik-dashboard-auth

  middlewares:
    traefik-dashboard-auth:
      basicauth:
        usersFile: "/etc/traefik/users"

  services:
    nginx:
      loadbalancer:
        servers:
          - url: "http://nginx:80"

    soketi:
      loadbalancer:
        servers:
          - url: "http://soketi:6001"

[raz1]

After multiple refreshes (!) I managed to make Chrome connecting to ws:

Could it be something related to the request headers?
In Firefox there is: Connection: keep-alive, Upgrade, but in Brave there is: Connection: Upgrade

[raz1]

Update:

After doing more investigations I discovered that if I'm opening the wss address in a new tab but with http protocol in front, I'm receiving 200 status and an "OK" message from my socket server which is soketi.

After doing this on Chrome everything works as expected, without any errors just like in Firefox.

Does anyone know how to handle this strange behavior?