Test query param issue

application.route\.js

import Route from '@ember/routing/route';

export default Route.extend({
});

application.template\.hbs

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

controllers.application\.js

import Controller from '@ember/controller';

export default class ApplicationController extends Controller {
  appName = 'Ember Twiddle';
}

loading.template\.hbs

Loading.... 

my-route.controller\.js

import Controller from '@ember/controller';

export default Controller.extend({
  queryParams: ['testParam', 'secondTestParam'],
  actions: {
   setQueryParam () {
     this.set('secondTestParam', Math.floor(Math.random() * 8)) 
   }
  }
});

my-route.route\.js

import Route from '@ember/routing/route';

function wait(milliseconds) {
  return new Promise(resolve => setTimeout(resolve, milliseconds));
}

export default Route.extend({
  queryParams: {
    searchParam: {
      refreshModel: true
    },
    secondSearch: {
     refreshModel: true 
    }
  },
  model () {
    return wait(2000)
  }
});

my-route.template\.hbs

<div>
Try to reproduce the query param issue:
<ol>
  <li>Make <LinkTo @route="my-route" @query={{hash 
  	searchParam="foo"
    secondSearch="bar"
    testParam="test"
  }}>Url</LinkTo>
</li>
  <li>Invoke a change so it's fresh load of route (while params present)</li> 
  <li>Click on Update button. Should see testParam become undefined</li>
</ol>

</div>
<div>
<button onclick={{action 'setQueryParam'}}>Update</button>

<div>{{testParam}}</div>

<div>{{secondTestParam}}</<div>

<div>{{searchParam}}</div>
<div>{{secondSearch}}</div>
</div>

router\.js

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

const Router = EmberRouter.extend({
  location: 'hash',
  rootURL: config.rootURL
});

Router.map(function() {
  this.route('my-route', {
   path: 'a-route' 
  })
});

export default Router;

twiddle\.json

{
  "version": "0.17.1",
  "EmberENV": {
    "FEATURES": {},
    "_TEMPLATE_ONLY_GLIMMER_COMPONENTS": false,
    "_APPLICATION_TEMPLATE_WRAPPER": true,
    "_JQUERY_INTEGRATION": true
  },
  "options": {
    "use_pods": true,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.5.1/jquery.js",
    "ember": "3.16.7",
    "ember-template-compiler": "3.16.7",
    "ember-testing": "3.16.7"
  },
  "addons": {
    "@glimmer/component": "1.0.0"
  }
}