Serjikz123_problem

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle'
});

controllers.categories.index.js

import Ember from 'ember';

export default Ember.Controller.extend({
  actions: {
		submit(category) {
			this.send('submitCategory', category);
		}
	}
});

router.js

import EmberRouter from '@ember/routing/router';
import config from './config/environment';

const Router = EmberRouter.extend({
  location: 'none',
  rootURL: config.rootURL
});

Router.map(function() {
  	this.route('categories', {
      resetNamespace: true,
      path: '/'
    }, function () {

      this.route('category1', {
        resetNamespace: true
      }, function () {
        this.route('configuration', {
          path: '/'
        });
      });
      
      this.route('category2', {
        resetNamespace: true
      }, function () {
        this.route('configuration', {
          path: '/'
        });
      });
    });
});

export default Router;

routes.categories.js

import Ember from 'ember';

export default Ember.Route.extend({
  actions: {
		submitCategory(category) {
			this.transitionTo(category);
		}
	}
});

routes.category1.configuration.js

import Ember from 'ember';

export default Ember.Route.extend({
  model() {
  	return new Promise(function (resolve) {
    	setTimeout( function() {
        console.log('1 resolved');
      	resolve();
      }, 2000);
    });
  }
});

routes.category2.configuration.js

import Ember from 'ember';

export default Ember.Route.extend({
  model() {
  	return new Promise(function (resolve) {
    	setTimeout( function() {
        console.log('2 resolved');
      	resolve();
      }, 2000);
    });
  }
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{outlet}}
<br>
<br>

templates.categories.index.hbs

<a href="#" onclick={{action "submit" "category1"}}>Category 1</a>
<a href="#" onclick={{action "submit" "category2"}}>Category 2</a>

templates.category1.configuration.hbs

Category 1 Loaded

templates.category2.configuration.hbs

Category 2 Loaded

twiddle.json

{
  "version": "0.15.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.js",
    "ember": "3.4.3",
    "ember-template-compiler": "3.4.3",
    "ember-testing": "3.4.3"
  },
  "addons": {
    "ember-data": "3.4.2"
  }
}