Managing Different builds

This is what I tried, and it is working perfectly except in development mode. Then the theming styles are not picked up. Any idea where I go wrong?

bud.config

app
    .entry({
      app: ['@scripts/app', '@styles/app'],
      editor: ['@scripts/editor', '@styles/editor'],
      theme1: ['@styles/theme1'],
      theme2: ['@styles/theme1'],
      ...
    })

setup.php

add_action('wp_enqueue_scripts', function () {
    bundle('app')->enqueue();
    
    $current_theme = get_field('choosetheme_r', 'options'); 

    switch ($current_theme) {
      case 'theme1':
        bundle('theme1')->enqueueCss();
        break;
      case 'theme2':
        bundle('theme2')->enqueueCss();
        break;
      ...

theme1.scss

@import 'theming/colors-theme1';
@import 'theming/fonts-theme1';