babel-loader not working, giving error on UglifyJS (ES6)

I have implemented the FlipClockJs vue component and it works fine when I run

yarn encore dev

However, as soon as I run

yarn encore production

I get the following error

ERROR Failed to compile with 1 errors12:30:24 PM

error

app.bc30a410.js from UglifyJs Unexpected token: operator (>) [app.bc30a410.js:12470,21]

I tried resolving this by adding this to my webpack file:

  .addLoader({
    test: /\.js$/,
    loader: "babel-loader",
    include: ['node_modules/@mvpleung/flipclock']
  })

But this just gives me the same result. My entire webpack file looks like this:

var Encore = require("@symfony/webpack-encore");
const { VueLoaderPlugin } = require("vue-loader");
const MinifyPlugin = require('babel-minify-webpack-plugin');

Encore.setOutputPath("public/build/")
  .setPublicPath("/build")

  .addEntry("app", "./resources/assets/js/app.js")

  .cleanupOutputBeforeBuild()
  .enableSourceMaps(!Encore.isProduction())
  .enableVersioning(Encore.isProduction())

  .addLoader({
test: /\.vue$/,
loader: "vue-loader"
  })
  .addLoader({
test: /\.js$/,
loader: 'babel-loader',
include: ['/node_modules/@mvpleung/flipclock']
  })
  .addLoader({
test: /\.(js|vue)$/,
enforce: "pre",
loader: "eslint-loader",
exclude: /node_modules/,
options: {
  fix: true
}
  })
  .addPlugin(new VueLoaderPlugin())
  .addPlugin(new MinifyPlugin())
  .addAliases({
vue: "vue/dist/vue.js"
  })

  .enableSassLoader()
  .enablePostCssLoader()
;

module.exports = Encore.getWebpackConfig();

Any idea what might be wrong here? The component works fine when running yarn encore dev.

Using Vue 2.5.17

from babel-loader not working, giving error on UglifyJS (ES6)