Why is my Telegram Webhook not triggering n8n behind a Cloudflare Tunnel?

Below is a list of troubleshooting points based on the known common issues with the Telegram Trigger node and webhook setups in n8n:

1. Reverse Proxy and Websocket Support

Even though your Cloudflare Tunnel provides external access, n8n often requires proper websocket handling when running behind a reverse proxy. Ensure that your Cloudflare Tunnel or reverse proxy settings are configured to support websockets. Without this, the Trigger node might appear to “listen” but never receive events.

2. HTTPS for Webhook URL

Telegram requires an HTTPS URL for webhooks. Although you mentioned that the WEBHOOK_URL is set to your external URL (using HTTPS), double-check that the URL (including any trailing slash or additional path) matches exactly what Telegram expects. If there's a slight misconfiguration, Telegram might register a webhook that doesn’t trigger the node.

3. Single Webhook Registration on Telegram

Telegram only allows one webhook per bot. If you use both a testing and a production webhook URL concurrently, Telegram will overwrite one with the other. Here are a couple of strategies to address this:

• Temporarily Disable the Production Workflow: While testing the Telegram Trigger node, disable your production workflow so that Telegram sends events only to the testing webhook.
• Create a Separate Testing Bot: Alternatively, set up a separate bot for testing and keep your production bot unchanged. This avoids conflicts in webhook registrations.

4. Verifying the Trigger

Since you are not receiving any messages or seeing any logs:

• Confirm Actual Telegram Activity: Ensure that you are sending a message or performing an action that should trigger the Telegram node.
• Check if the Node is Stuck in Listening Mode: If you’re testing via the n8n interface (using “Test Workflow”), sometimes the node might appear to be stuck. In that situation, try exiting the workflow and reopening it to reset event listening.

Final Checklist

• Verify your Cloudflare Tunnel (or reverse proxy) configuration supports websockets.
• Ensure WEBHOOK_URL is correctly set with HTTPS and matches how Telegram registered the webhook.
• Avoid any overlap with testing and production webhook URLs (use one at a time or separate bots).
• Manually trigger an event from Telegram that should reach the Trigger node.
• Restart the workflow (or n8n instance) to clear any stale listening state.

Following these steps should help you determine why the Telegram Trigger isn’t capturing events even though the connection test is successful.