Hi there,
I checked the CPFA page and I see what you mean. As soon as I remove the code from the COntent Element it is working ok and I put the code and it fails.
And you are right the name of the mode is Skeleton mode. I checked the code and I think the reason is the Javascript inside which tries to document.write
write something into the document.
Now the Cornerstone and all other Front End page builders use the iFrame technology to render the actual website and as the code tries to add something inside the document, it is added to the whole document of the backend instead f the iFrame inside.
Think of a big window which as smaller window inside. That smaller window has no problem with the code when checked separately in the front end without the big window.
But as soon as it is inside the big window the code adds the script to the big window instead of the small window and ruins the whole thing.
Unfortunately, there is nothing can be done in this situation. You either need to continue using Skeleton mode or remove the code and save and reload and start your editing and in the end, add the code again for each edit.
Thank you for your understanding.