Customizer shows no sections on page

Hello,

I have a page: https://goo.gl/77Ddmo

It has content, however, when I go to the page customizer it comes up with no content in the manage page sections. This appeared as I was editing a subpage (not the main page) but appears to affect the main page as well.

I tried to disable all plugins, that didn’t help. Disable cloudflare cache of course, that didn’t help either. It’s across multiple browsers, so it appears to be a file or setting problem.

Please assist.