Not really an undergoing issue as I managed to solve this.

Context:

I was trying to make a contact Webhook form work when deploying on Vercel. When website was published on wstd subdomain, the form worked correctly and sending a POST to n8n.

This was the payload sent on submit:

Notice the "ws--form-id" parameter is populated with "action".

When deploying on Vercel, the value for "ws--form-id" parameter was empty:

This resulted in an error:

Solution:

Manually set the "ws--form-id" parameter in the Webhook Form settings:

Not sure why this is happening, but I hope helps you debugging and other users with the same headache :)

Love the product btw!

Giacomo