sound and Artefact shadow because of SceneOptimizer

Hi,

When I activate the music on my scene (with a lot of object)  and if use SceneOptimizer, I get the ripples of the music on the ground in the form of a shadow.

It happens when I use:  mesh.material.freeze();

See screenshot.

The code is :

this.music = new BABYLON.Sound("musicZone", "myMP3.mp3", this.scene, null, { volume: 1.0, loop: true, autoplay: true, streaming: true, spatialSound: false }); 

BABYLON.SceneOptimizer.OptimizeAsync(scene, optionOptimizer());	

    function optionOptimizer()
	{
		var result = new BABYLON.SceneOptimizerOptions(60, 1000);
		result.optimizations.push(new BABYLON.ShadowsOptimization(0));
		result.optimizations.push(new BABYLON.LensFlaresOptimization(1));
		result.optimizations.push(new BABYLON.TextureOptimization(2, 256));
		result.optimizations.push(new BABYLON.PostProcessesOptimization(3));
		result.optimizations.push(new BABYLON.ParticlesOptimization(4));
		result.optimizations.push(new BABYLON.RenderTargetsOptimization(5));
		result.optimizations.push(new BABYLON.HardwareScalingOptimization(6, 4));
		return result;
	}