Classic Paragraph content disappeared

Hi community,

I am using the Zakra theme. I created a site with the gutenberg Block editor. Suddenly some content is dissapeared in a classic pharagrap. It was a text with some links. It is also not possible to make a revision. Here you can find a screenshot.

What can I do?

It is also happened to some pictures on another site. It was also a classic paragraph.

Thank you

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