New Twiddle

controllers.application.js

import Ember from 'ember';

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

controllers.index-loading.js

import Ember from 'ember';
import { inject as service } from '@ember/service';
import { readOnly } from '@ember/object/computed';

export default Ember.Controller.extend({
  foo: '42',
  bar: 'hmmm',
});

routes.index-loading

import Ember from 'ember';

export default Ember.Route.extend({
  model() {
    console.log('here');
    return 25;
  }
});

routes.index.js

import Ember from 'ember';

export default Ember.Route.extend({
  model() {
    return { then() { } };
  }
});

templates.application.hbs

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

templates.index-loading.hbs

<div>index-loading</div>
<div>to reproduce issue, go to /?bar=something</div>
<div>foo is {{foo}}</div>
<div>bar is {{bar}}</div>

twiddle.json

{
  "version": "0.15.0",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.js",
    "ember": "3.2.2",
    "ember-template-compiler": "3.2.2",
    "ember-testing": "3.2.2"
  },
  "addons": {
    "ember-data": "3.2.0"
  }
}