Messed up on Back End and Front End

After updating to the latest version, on some of my pages that have a text block, the text is scrambled and unformatted and not readable – doesn’t even look like html. This only happens when i am logged in as an administrator and happens in front and back end. After a log out, everything is ok.

Please check an example in the image I have attached: https://ibb.co/mzYGCHd

Thanks

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