Cloudflare Tunnel - WebSocket connection fails after LetsEncrypt add-on uninstall

Third party integrations
1

Hi everyone,

I'm having an issue with remote access to Home Assistant via Cloudflare Tunnel. It stopped working about a week ago after I tried to configure the LetsEncrypt add-on (which I then uninstalled).

My setup:

  • Hardware: Home Assistant Green
  • HA OS: 17.3 (aarch64)
  • HA Core: 2026.5.1
  • Cloudflared add-on: 7.0.6
  • Domain: OVH domain with Cloudflare proxy (orange cloud)
  • SSL/TLS Cloudflare mode: Full (strict)
  • No Nginx Proxy Manager

What works:

  • Local access via http://192.168.1.10:8123 :white_check_mark:
  • Cloudflare Tunnel connects successfully (4 connections registered in logs) :white_check_mark:
  • Login page loads on https://42rdfdt.fr :white_check_mark:

What doesn't work:

  • After login, browser shows "Unable to connect to Home Assistant. Retrying in X seconds."
  • Firefox console shows: Firefox can't establish a connection to the server at wss://42rdfdt.fr/api/websocket
  • Chrome shows: ERR_SSL_VERSION_OR_CIPHER_MISMATCH

What I've already tried:

  • WebSockets enabled in Cloudflare Network settings :white_check_mark:
  • SSL/TLS set to Full (strict) :white_check_mark:
  • Added trusted_proxies in configuration.yaml
  • Deleted /ssl/fullchain.pem and /ssl/privkey.pem left by LetsEncrypt add-on
  • Disabled Rocket Loader via Cloudflare Configuration Rule
  • Cleared Firefox cache and cookies for the domain
  • Tested on 4G (mobile hotspot) — same issue

My current configuration.yaml:

yaml

default_config:

frontend:
  themes: !include_dir_merge_named themes

automation: !include automations.yaml
script: !include scripts.yaml
scene: !include scenes.yaml

http:
  use_x_forwarded_for: true
  trusted_proxies:
    - 172.30.32.0/24
    - 172.30.33.0/24
    - 172.30.32.1
    - 127.0.0.1
    - ::1
  ip_ban_enabled: false

homeassistant:
  external_url: "https://42rdfdt.fr"
  internal_url: "http://192.168.1.10:8123"

Cloudflared add-on configuration:

  • External hostname: 42rdfdt.fr
  • Tunnel name: homeassistant
  • No additional hosts
  • Post-quantum cryptography: disabled

Cloudflared logs show no errors — tunnel connects perfectly to Cloudflare edge servers.

Any help would be greatly appreciated. Thank you!

2

Have you looked at your CloudFlared app logs?

Review this Fix VERSION_OR_CIPHER_MISMATCH · Cloudflare SSL/TLS docs

If your visitors experience ERR_SSL_VERSION_OR_CIPHER_MISMATCH (Chrome) or SSL_ERROR_NO_CYPHER_OVERLAP (Firefox), check the status of your Universal certificate:

  1. Log into the Cloudflare dashboard :up_right_arrow:.
  2. Choose your account and domain.
  3. Go to the Edge Certificates :up_right_arrow: page.
  4. Find the certificate with the Type of Universal.
  5. Make sure the Status is Active.

If the Status is anything other than Active, you can either wait a bit longer for certificate activation or take immediate action.