Firefox中注册使用ES模块的Service Worker时抛出TypeError导致注册失败求助

大家好，我最近碰到个棘手的问题：在Firefox里注册用ES模块的Service Worker时总是失败，抛出了TypeError，但这套代码在Chrome、Edge和Opera里都能正常跑，实在摸不清头绪，来求助各位！

错误信息 #

注册失败时的提示是：

SW Registration failed with TypeError: ServiceWorker script at http://localhost/Vanilla/CacheManager.js for scope http://localhost/Vanilla/ threw an exception during script evaluation.

我的Service Worker注册代码 #

if ("serviceWorker" in navigator) {                 
    await navigator.serviceWorker.register('/Vanilla/CacheManager.js', { scope: '/Vanilla/', type: 'module' })
        .then(reg => {
                console.log('SW Registered');
            })
        .catch(err => {
            console.log('SW Registration failed with ' + err)
        });
}

简化后的CacheManager.js代码 #

问题就出在导入语句这一行：

import config from "/Vanilla/config.js" // The problem
console.log("Hello")
//const CACHE_NAME = config.cacheName   

对应的Config.js代码 #

export const config = 
{
    "cacheName": "VanillaV1.1"
}

我完全搞不懂Firefox到底在抱怨什么TypeError，难道是CONST的问题吗？有没有朋友遇到过类似情况，或者能帮我排查下问题根源？

备注：内容来源于stack exchange，提问作者McMurphy