Problem with Telegram Send and Wait for Response in Loop (n8n on Railway)

[DOLOWW73]

Hi,

I’m having issues using the Telegram Send and Wait for Response node in a loop in n8n (hosted on Railway). The first message works, but from the second iteration I get invalid URL errors with the webhook button.

I’ll provide screenshots for details. Looking for advice on how to handle multiple Send and Waits in one workflow.

Thanks!

[darrell_tw]

Bad Request: inline keyboard button URL
'$({RAILWAY_PUBLIC_DOMAIN/webhook-waiting/68/a7eedd69-2268-43ba-ba81-f9394a9bb523?approved=true' is invalid: Disallowed character in URL host

Can you provide where you use the expression?

The '$({RAILWAY_PUBLIC_DOMAIN

[DOLOWW73]

I don’t have to give it to any node, I think it’s generated by the Send and Wait node. It’s the link that appears under a Telegram message — the one I’m supposed to respond to.

[darrell_tw]

Okay, after some testing, I think there’s a bug on your end in some special circumstances.

When the workflow runs for the second time, the Telegram node cannot get the correct webhook URL from your setting ${RAILWAY_PUBLIC_DOMAIN}, so the button url on Telegram break.

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It’s working fine on my end though.
The possible cause might be Railway or something fundamental or platform level issue.