PixiJS on Meteor with router

I am working on a project using Meteor with Pixi.js, and I'm facing a very strange problem when I try to use a router (I tried both IronRouter and FlowRouter), and a pixi canvas.

The canvas is built, but i cant render any sprite on it. This happen only when i use a route parameter, such as '/game/:id'

This is working except when i use a route parameter, such as '/game/:id' More, if i dont use route parameter, Sprite is showing up when i access '/game' Sprite doesn't show up when i access '/game/

Here is a minimal error code on a meteor app :

Any Router definition :

Router.route('/room/:_id', {
    action: function() {
        this.render('game');
    }
});

A basic template : Html :

<template name="game"></template>

Js :

Template.game.onRendered(function () {
PIXI.loader.add("assets/mario.png")
    .load(() => {
        let app = new PIXI.Application();
        document.body.appendChild(app.view);
        let mario = new PIXI.Sprite(PIXI.loader.resources["assets/mario.png"].texture);
        mario.position.set(5, 5);
        mario.width = 48;
        mario.height = 48;
        app.stage.addChild(mario);
        app.render();
    });
});

The pixi canvas will show up but mario sprite doesn't.