Thanks for providing the details.
I spent some time testing your setup and downloading your page to my local setup and I am getting the same issue. I have also tried importing the non-profit demo and I got the same issue for some of the Classic Custom Headline elements.
I did further testing an found out that having an
<hr> code to the Classic Custom Headline element triggers an issue to the page.
I have already noted this and added it to our issue tracker so that our developers will be aware of it.
We apologize for the inconvenience but for the meantime, kindly edit the Classic Custom Headline element in Skeleton mode and remove the
<hr> codes inside it.