TypeScript enum is undefined on Webpack imported module

In an Electron application, I'm using the latest Webpack (5.74.0) to generate a bundle for the renderer process. The bundle generates fine, but I'm getting undefined when trying to access a property on an imported module that represents an enum value.

Here's how my import is declared:

import { SessionViewType } from "util/types";

The types file exports this enum:

export enum SessionViewType {
    SAVED = "SAVED", NEW = "NEW", DELETE = "DELETE"
}

Oddly enough, if I explicitly add the .ts suffix to the import, the error goes away:

import { SessionViewType } from "util/types.ts";

This only affects enums - the issue also applies to imported third-party modules that use enums.

Here's my Webpack configuration for the renderer:

const { resolve } = require('path');
const { VueLoaderPlugin } = require('vue-loader');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const polyfillPlugin = require("node-polyfill-webpack-plugin");

module.exports = {
    entry: './src/renderer/entry-point.ts',
    target: "electron-renderer",
    output: {
        path: resolve(__dirname, 'dist', 'renderer'),
        filename: 'renderer.js'
    },
    resolve: {
        alias: {
            css: resolve(__dirname, "src/renderer/css"),
            component: resolve(__dirname, "src/renderer/component"),
            img: resolve(__dirname, "src/renderer/img"),
            util: resolve(__dirname, "src/renderer/util")
        },
        extensions: ['.vue', '.js', '.ts']
    },
    module: {
        rules: [
            {
                test: /\.scss$/,
                use: [
                    'vue-style-loader',
                    'css-loader',
                    'sass-loader',
                ]
            },
            {
                test: /\.ts$/,
                exclude: /(node_modules)/,
                use: [
                    {
                        loader: 'ts-loader',
                        options: {
                            transpileOnly: true,
                            appendTsSuffixTo: [/\.vue$/]
                        }
                    }
                ]
            },
            {
                test: /\.vue$/,
                exclude: /(node_modules)/,
                loader: 'vue-loader'
            },
            {
                test: /\.(png|jpe?g|gif|svg)$/,
                type: "asset/resource"
            }
        ]
    },
    plugins: [
        new VueLoaderPlugin(),
        new HtmlWebpackPlugin(),
        new polyfillPlugin({
            includeAliases: ["path"]
        })
    ],
    node: {
        global: true
    }
};