Why Marzipano is not showing the image on mobile devices (browsers)

I am using Marzipano to display 360-grade images of specific places on my website. It is working fine on desktop and laptop devices (browsers) but not on mobile. Below is the code:

// Create viewer
var viewer = new Marzipano.Viewer(document.getElementById('pano'));

// Create a source
var source = Marzipano.ImageUrlSource.fromString("");

// Create geometry.
var geometry = new Marzipano.EquirectGeometry([{ width: 4000 }]);

// Create view.
var limiter = Marzipano.RectilinearView.limit.traditional(1024, 100*Math.PI/180);

var view = new Marzipano.RectilinearView({ yaw: Math.PI }, limiter);

// Create scene.
var scene = viewer.createScene({
    source: source,
    geometry: geometry,
    view: view,
    pinFirstLevel: true
});

// Display scene.
scene.switchTo();

Is it any kind of image size restrictions on mobile browsers or what do you think the problem is?

Thank you!