Problems with scoped styles in Vue

[fractalf]

Is there a problem with having scoped styles in Vue in Laravel?
This is such a core feature in Vue I can't understand why it's not working.

First when adding <style lang="scss" scoped> all the style was just ignored.
Then I tried this

   .sass('resources/sass/app.scss', 'public/css', {
      implementation: require('node-sass')
   })

and at least the style was working, but it's leaking to child components!

ref #2376 #1850 (comment)

[fractalf]

As often shows this was just me not really understanding how this works.
Oh and https://vue-loader.vuejs.org/guide/scoped-css.html#child-component-root-elements