Duplicate first app load

I'm experiencing a strange behavior and I'm not sure if it's a bug.
When I start my app it always fires two api requests. It looks like the app loads and then it reloads the second time.

I've created a new ember project and the same happens.
Just a route call:
``` javascript
export default Route.extend({
model() {
return fetch('http://localhost:3333/me')
}
});
```

inspector:

and the server:

When it loads, all other api calls are fired only once and it only happens when fastboot is enabled.

My packages:
```
"broccoli-asset-rev": "^2.4.5",
"ember-ajax": "^3.1.0",
"ember-cli": "^3.3.0",
"ember-cli-app-version": "^3.0.0",
"ember-cli-babel": "^6.6.0",
"ember-cli-dependency-checker": "^2.0.0",
"ember-cli-eslint": "^4.0.0",
"ember-cli-fastboot": "^1.1.4-beta.1",
"ember-cli-htmlbars": "^2.0.1",
"ember-cli-htmlbars-inline-precompile": "^1.0.0",
"ember-cli-inject-live-reload": "^1.4.1",
"ember-cli-qunit": "^4.0.0",
"ember-cli-shims": "^1.1.0",
"ember-cli-sri": "^2.1.0",
"ember-cli-uglify": "^2.0.0",
"ember-data": "^2.16.4",
"ember-export-application-global": "^2.0.0",
"ember-fetch": "^5.1.1",
"ember-load-initializers": "^1.0.0",
"ember-resolver": "^4.0.0",
"ember-source": "~2.16.0",
"ember-welcome-page": "^3.0.0",
"loader.js": "^4.2.3"
```

How can I prevent this? I'm making some token invalidation and it is screwing things up.