Hello and thank you for your reply!
I’m not sure this is what you want to know, but the page seems to be built using the basic, out-of-the-box WYSIWYG editor. But in multiple instances; one for each section of the page, instead of having all the different sections in a single editor window.
Again, I don’t remember seeing this before and can’t really explain the reasoning behind it as I wasn’t involved in the development of this custom theme.
I’m including two screenshots. The first one shows the muliple editors (there is one in each “tab”). The second one shows what Yoast reads. Please excuse the French — it says therer is not enough content for SEO, and 0 words for content quality. So I’m thinking it simply doesn’t see any content at all from all the visual editors…
https://exob2b.com/pics/editors.jpg
https://exob2b.com/pics/yoast.jpg