Babylon js texture issue when used with reactjs

I'm implementing 3D demo application using Babylonjs library for 3D Demo.I'm importing 3D model from S3 and adding texture image on top of material in Reactjs. But when i add texture image on top of material, rest of area on 3D model gets black color and i want get rid of it. Code works fine in Babylon playground but fails in React app.

Here is the source code

var mat = new BABYLON.CustomMaterial("mat", scene);
    mat.diffuseTexture = new BABYLON.Texture(textureImage, scene, false, false);
    materialedMeshes.forEach(mesh => mesh.material = mat);
    mat.emissiveColor = new BABYLON.Color3(1, 1, 1);
    
    // mat.diffuseColor = new BABYLON.Color3(1, 0, 1);
    // mat.specularColor = new BABYLON.Color3(0.5, 0.6, 0.87);
    // mat.emissiveColor = new BABYLON.Color3(1, 1, 1);
    // mat.ambientColor = new BABYLON.Color3(0.23, 0.98, 0.53);

    mat.diffuseTexture.uOffset = -0.1000;
    mat.diffuseTexture.vOffset = -1.1800;
    mat.diffuseTexture.uScale = 1.2200;
    mat.diffuseTexture.vScale = 2.2200;
    mat.diffuseTexture.uAng = Math.PI;
    mat.diffuseTexture.wrapU = BABYLON.Constants.TEXTURE_CLAMP_ADDRESSMODE;
    mat.diffuseTexture.wrapV = BABYLON.Constants.TEXTURE_CLAMP_ADDRESSMODE;
    mat.Fragment_Custom_Alpha(`
    if (baseColor.r == 0. && baseColor.g == 0. && baseColor.b == 0.) {
        baseColor.rgb = vec3(0.85, 0.85, 0.85);
    }
    baseColor.rgb = mix(vec3(0.85, 0.85, 0.85), baseColor.rgb, baseColor.a);
`)