Unable to edit classic page

Hello, I am using Gutenberg and getting on reasonably well. Problem is I have a page titled (plant-encyclopedia) Its been a page on my site for a number of years, I add to it on a regular basis. It is an old page so I have to access using classic. When I now go in to edit, the pictures are not showing, therefore, I am unable to add new images. If I go to preview everything looks normal. Alistair

The page I need help with: [log in to see the link]