Why isn't my form updating on preview?

I'm testing your software to see if it will meet our needs for small event registration. However, I  created a form last Friday and today have modified it with a new header graphic - but when I move to preview mode, it still shows the old form. What is the issue?

I have just checked your form and I can see it shows the same version like the form builder: 

I would recommend you to try clearing your browser cache since, I also cleared your forms cache from our end. 

Please let us know if the issue persists.