Applied Theme Disappears if Form is Edited

trying to use theme in this form. i save it but it keeps disappearing if I come back to it or change some of the design.

Do you mean that you are attempting to apply a theme from our theme store to your form and that is what keeps disappearing on your form? Or?

Which theme are you trying to apply to it that isn't working on your end?

When I check your form this is what I currently see below -