I’m having a similar problem. But only on one page. Mine does not look exactly like the link from above. I don’t know how to send you a link to the editing image of my page but here is a link to the page on my site. https://autoimmuneroots.com/my-food/food-symptom-diary/. It happened when I switched to HTML to embed a link to a google spreadsheet. Now I can’t get back to regular visual editing. The page looks fine on my site. It is just stuck in this mode & the menu bar that allowed me to switch back & forth is gone. Other posts are fine when I edit them. It is just this post.