FireFox, Loading JS that block all the rest of the page loading... (FireFox)

Hi everyone,

In my page I have something like :

<!DOCTYPE html>

<html lang="en">


<head>

    <title>A title</title>

    <meta charset="utf-8">

    <script src="https://something.com/Script.js"></script>

</head>

But if for any reason the

<script src="https://something.com/Script.js"></script>

can’t load on the user Internet browser ex: (firewall, something.com offline etc…)

Then the loading and CSS animation ! (WTF) of the page is on hold until (I assume) the browser timeout trigger and the rest of the page continue to load.

I’ve try to put the script at the bottom of the HTML code but doesn’t help,

neither:

<script src="https://something.com/Script.js" type="module" async></script>

Any ideas ?