Is there any overall solution to this problem?
I am helping a client set up this page https://www.climatepolicylab.org/rddmap
And having any instance of <iframe /> in either an Embed or Code block causes the main nav and footer to disappear. They are still present in the DOM when I inspect using the web inspector, but they are not visible, though they appear just fine in the page edit UI. In testing, I can have script tags or other HTML without causing this issue.
Here's what you see on the backend, note the navigation at the top:
But when you save and view that page as a regular site visitor, you get no nav or footer:
If I take the iframe out, presto, nav and footer come back... And when I look at the source code for the page, all the HTML is still there. I'm a bit stumped about what could be going on here.