The fetching isn't working properly

Hi there,

I hope you can help me. I did the smushing and I got the Email. So I pressed the button that says Fetch smushed images and it is running for hours without anything happening. I refreshed the page and suddenly 1 picture was finished. So I pressed the button again... same happened. When I refreshed another picture was fetched. Why is it not working properly?

All the best,
Corinna