Filter not loaded on first load, mobile

[md_lasalle]

Hi, I'm currently developing a game where in the preload phase I load a few images and a shader :

this.load.image('title', 'assets/images/title.png');
this.load.image('subtitle', 'assets/images/subtitle.png');
this.load.image('particle', 'assets/images/particle.png');
this.load.bitmapFont('belleza', 'assets/fonts/belleza.png', 'assets/fonts/belleza.xml');
this.load.shader('sphere', 'assets/shaders/sphere.frag');

Unfortunately it seems that on mobile (tested chrome + safari on iphone5s running iOS 10), the page requires a reload for the filter to work.

Any idea what I should be looking for? Desktop browser version works fine.

Thanks.

[md_lasalle]

Just to add a little bit of info, I don't get any error code in the javascript console. I'm thinking that if on mobile, I'm going to force a page reload the first time the user loads it to circumvent this issue.