Themes not working on my forms

Hello, I'm trying to create a form but I can't apply any theme to the form. Also, every question appears on the separate page.

Here are the screenshots:

This is the screenshot of the build page

In the added file is a screenshot of preview (it looks different)

Thank you.

I checked your account and I can see that you're a new user that has the next generation of JotForm forms. That's the reason why your new form is looking like you described. 

As for the adding theme that is not working, I cloned your form and I was able to change a theme without having any issue. Here's a screen animation:

Could you please try it again? If the issue persists, try a different internet browser.

Let us know how it goes. Thank you.