Hey @deet_dev! FilesInputStore.FilesToLoad is designed to be a cache where the file names are always stored in lowercase, so if you change your code to this:
selectedFiles.forEach(file => {
FilesInputStore.FilesToLoad[file.name.toLowerCase()] = file;
});
Then it should work correctly. I will work on updating our docs to make this clearer.
Unrelated to your question, SceneLoader is deprecated, so I would recommend you use instead the BABYLON.ImportMeshAsync function instead, you can read the docs here:
ImportMeshAsync | Babylon.js Documentation
And here is a playground:
ImportMeshAsync Example | Babylon.js Playground
Hope it helps!