Reproduction of child nav with queryparams

controllers.application\.js

import Controller from '@ember/controller';
import { tracked } from '@glimmer/tracking';
import { inject as service } from '@ember/service';
import { action } from '@ember/object';

export default class Application extends Controller {
  @service router;
  
  queryParams = ['filter', 'sort'];

  @tracked filter = '';
  @tracked sort = '';

  /**
   * This _kinda_ makes sense, because this sets the query params on transition
   * and setting invalidates tracked properties. 
   *
   * here, it does not matter what the value of the query params are, the
   * model hook _always_ re-runs (it shouldn't)
   *
   * maybe if the qp properties had some value-based-caching / memoization to prevent
   * unneeded invalidation, that would solve the problem?
   */
  @action
  reproductionWithHrefs(e) {
    e.preventDefault();
    
    if (this.router.isActive('child')) {
      return this.router.transitionTo(`/?filter=${this.filter}&sort=${this.sort}`);
    }
      
    this.router.transitionTo(`/child?filter=${this.filter}&sort=${this.sort}`);
  }

  /**
   * Even when the query params are omitted (falling back to sticky behavior),
   * the model hook still re-runs (it shouldn't)
   */
  @action 
  reproductionWithDotNotation(e) {
    e.preventDefault();
    
    if (this.router.isActive('child')) {
      return this.router.transitionTo('application');
    }
      
    this.router.transitionTo('child');
  }

  @action 
  worksButDeprecated(e) {
    e.preventDefault();
    
    if (this.router.isActive('child')) {
      return this.transitionToRoute('application');
    }
      
    this.transitionToRoute('child');
  }
}

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('child');
});

export default Router;

routes.application\.js

import Route from '@ember/routing/route';
import { tracked } from '@glimmer/tracking';

class InvocationTracker {
   @tracked count = 0; 
}

export default class Application extends Route {
  tracker = new InvocationTracker();

  queryParams = {
    filter: {
      refreshModel: true,
    },
    sort: {
      refreshModel: true,
    },
  };

  async model() {
    this.tracker.count++;

    return this.tracker;
  }
}

templates.application\.hbs

<header>
  <h1 style="font-size: 1.5rem">
  	Repro for <a target="_blank" href="https://github.com/emberjs/ember.js/issues/19497">emberjs/ember.js#19497</a>
  </h1>
  <em style="font-size: 0.75rem">
    Mentioned here as well:
    <a href="https://github.com/emberjs/rfcs/pull/674#discussion_r517865936">RFC #674 (comment)</a>
  </em>
</header>

<br>
<br>

<nav style="display: flex; gap: 1rem">
  <a href="#pretendThisIsValid" {{on 'click' this.reproductionWithHrefs}}>Toggle "WithHrefs"</a>
  <a href="#pretendThisIsValid" {{on 'click' this.reproductionWithDotNotation}}>Toggle "WithDotNotation"</a>
  <a href="#pretendThisIsValid" {{on 'click' this.worksButDeprecated}}>Toggle "worksButDeprecated"</a>
</nav>


<hr>

# of parent model invocations: {{@model.count}}

{{outlet}}

templates.child\.hbs

Child route

twiddle\.json

{
  "version": "0.17.1",
  "EmberENV": {
    "FEATURES": {},
    "_TEMPLATE_ONLY_GLIMMER_COMPONENTS": false,
    "_APPLICATION_TEMPLATE_WRAPPER": true,
    "_JQUERY_INTEGRATION": true
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.5.1/jquery.js",
    "ember": "3.18.1",
    "ember-template-compiler": "3.18.1",
    "ember-testing": "3.18.1"
  },
  "addons": {
    "@glimmer/component": "1.0.0"
  }
}