How to show forms in iframes in "Rich Text" fields? Works for views, not for forms

I set up a rich text field and inserted as html the iframe snippet for a view, and it works well. However, fields do not show when the same is done for forms. The header shows, as does the sliders; however field names and the fields themselves do not. I tried customizing field sizes and colors, but it makes no difference. Also not shown if done as a form-perma, though again the view equivalent works fine.

Would make it neat to insert affiliated forms into other forms and even into views, were it possible.