hi
When a brand‑new WhatsApp contact triggers our automation by sending a massage throught a url , the system sends the intended first message and immediately follows it with an unsolicited message that contains only the character “0”. This extra “0” is not configured anywhere in our flow and does not appear for contacts who have already chatted with us before.
Hi,
That's odd...
Have you checked if there's nothing enabled as “default reply”?
I also suggest taking a look in your Meta Business Suite. There are some automation options that could also be the source of this mysterious 0.
I checked, and there is no WhatsApp template message that includes a “0”, although the “0” only appears when a new contact sends a message.
You will probably need to get in contact with Manychat's Support Team to check that… 
How to get support from Manychat – Manychat Help
Meta has also “welcome messages” for WhatsApp, but this seems to have some bug and is disabled at the moment: https://developers.facebook.com/docs/whatsapp/cloud-api/phone-numbers/conversational-components
Anyway… the support team will be able to investigate it further...
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