Laravel - Error 502 "Bad Gateway" when using a email:dns validation

I use Laravel (v9.52.16) with Inertia.

In front-end (Vue.js) I have an email field and in back-end (PHP 8.1.22) I do validations. I use RFC and DNS validationsto authorize only valid emails with valid DNS. (https://laravel.com/docs/9.x/validation#rule-email).

Everything works fine, for valid email and invalid email, but my QA team tried the email not@valid.com. But for this one, it triggers the Error 502 "Bad Gateway" after 10s waiting for the server response.

Request::validate([
'email' => ['required', 'email:rfc,dns'],
]);


What you need to know:

• On localhost it works
• This problem was found on my test environment hosted on AWS, it doesn't works
• not@valid.com seems valid, but with the Error 502 I'm not sure
• not@valid.ca is valid
• not@valid.comm is not valid
• I tried without the DNS validator ('email:rfc') the email is valid

I was wondering if the problem wasn't coming directly from DNS, because everything works with the rest. So I got the domain information, but I can't find anything that explains the problem.

https://www.whois.com/whois/valide.com (DNS not working)
https://www.whois.com/whois/valide.ca (Working DNS for comparison)

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