Vuetify styles are missing after update

[lephro]

Hi,

all vuetify styles (Buttons etc.) are missing, after I updated this packages:

• vuetifyjs-mix-extension (0.0.17) --> (0.0.20)
• vuetify-loader (1.6.0) --> (1.7.1)
• laravel-mix (5.0.9) --> (6.0.11)

Did I do everything right?

webpack.mix.js

const mix = require('laravel-mix');

require('vuetifyjs-mix-extension')

mix.options({    
  processCssUrls: false, 
  runtimeChunkPath: 'js' 
})

mix.webpackConfig(require('./webpack.config'));

mix.autoload({ 
  jquery: ['$', 'window.jQuery', 'jQuery'],
})

mix.js('resources/js/app.js', 'public/js') 
   .vuetify('vuetify-loader', 'resources/styles/variables.scss')
   .vue()
   .sass('resources/styles/app.scss', 'public/css')
   .sourceMaps(false); 

if (mix.inProduction()) {
  mix.version();
}