My items are not showing in my studio

Despite my launcher saying the item was successfully uploaded, certain lots (and more recently, a world I created) are simply not showing up in my studio.

I've tried deleting and re-uploading, but nothing.

Why does this happen?
How can I get it to work?

Anyone?

I wish I knew, it is happening to me too - for over a month now. Says item is uploaded, but not in studio. I am very frustrated so if anybody knows please tell us how to fix this.