Single-spa subapp renderd but not displaying

Question

I have a main app using Nuxt2 and Vue. And I try to add a microfrontend using single-spa library. The subapp rendered in the main app without any errors but it is not displaying. I also use vue-i18n. Asynchronous functions in plugins section which are required for localization cause display issue in subapp. If I comment asynchronous functions there is no issue in the subapp, but it chusches localization. Without single-spa asynchronous functions in plugins section work well.

localization.js in plugins folder

export default async function boot(context) {
 await context.store.dispatch('auth/getUser');
 await Promise.all([
 context.store.dispatch('ui/updateDefaultLanguage'), //some asynchronous functions cause issue in subapp
 context.store.dispatch('auth/getConfiguration'),
 ]);
}

nuxt.config.js

plugins: [
//...
    'plugins/localization.js',
    'plugins/root-application.client.js',
  ],

Link to sandbox which I have used as an example of initial project.