Localhost (http://localhost:5678/) error when using e.g. Slack or Gmail "Send and wait. for response" nodes

[Simpson007]

Title: Localhost error (http://localhost:5678/) when using e.g. Slack or Gmail “Send and wait for response” nodes

n8n Version: 1.12.4

Instance Type: Self-hosted (Docker with Hostinger)

Problem:

Gmail “Send Message and Wait for Response” node generates approval links pointing to http://localhost:5678 instead of my configured domain, causing “connection refused” errors when recipients click the links.

Environment Variables in docker-compose.yml:

yaml

- N8N_HOST=${SUBDOMAIN}.${DOMAIN_NAME}
- N8N_PROTOCOL=https
- WEBHOOK_URL=https://${SUBDOMAIN}.${DOMAIN_NAME}/
- N8N_EDITOR_BASE_URL=https://${SUBDOMAIN}.${DOMAIN_NAME}/
- N8N_PROXY_HOPS=1
```

Verified inside container via:

bash

docker exec <container_name> printenv | grep -E "N8N_HOST|WEBHOOK_URL|N8N_PROTOCOL|EDITOR|PROXY"

Output confirms variables resolve correctly to subdomain.mydomain.com

What works:

• Regular Webhook nodes show correct URL (both Test and Production)

• Accessing n8n via subdomain.mydomain.com works fine

What doesn’t work:

• e.g. Gmail “Send and Wait for Response” approval links still use localhost:5678

Setup:

• Docker Compose

• PostgreSQL database

• Redis queue mode

Already tried:

• Cleared browser cache

• Created new webhook nodes

• Restarted containers multiple times

• Restarted VPS

• Added N8N_PROXY_HOPS=1

Any help appreciated!!! Unfortunately this issue has not been solved also it was mentioned couple of times in the forum here in older threads.

[Mookie_Lian]

Check if you added the correct redirect URI for your credentials in Google Console(for Gmail).

The redirect URI is usually as follows:

https://your-full-address-here/rest/oauth2-credential/callback

You also have to confirm using the same way for Slack Developer Platform.

[Simpson007]

Yes, added it in Google Cloud.

Reconnected Google Tools in n8n and still receive the error….

[Simpson007]

Solution found!

The issue was the queue mode of the n8n instance. It finally works after being downgraded via Hostinger!

Hope this helps other people.