Background image not showing in the Advance Designer?

One more thing, every time I go to the advanced Designer, I lose my background image. Why is that? This form is embedded on our website and it makes me nervous to make changes on the design. So I just X out of it.

https://www.screencast.com/t/AYjbqZnt

I have tested the background image with a test form and the feature seems to be working fine. It looks like the theme used for the form or CSS code injected to the form is conflicting with the form design causing the issue. I have tried cloning the form to my account and changed the theme to default without any CSS and it seems to be working fine.

Since there are some changes already made to your JotForm and the issue is form specific, you may check the preview after any changes you made to the form. 

Hope this information helps!