Invalid input in "Content" Failed to save entry: Form validation failed, please check your input

Some pages of the site do not save content after changes. Perhaps due to the fact that these pages have the most content. Other pages with similar content are saved normally. So I think it’s about the amount of content.
If you make edits to the .md page file, they are displayed correctly. Problem when editing from admin panel.
How fix this error?
(Grav v1.7.35 - Admin v1.10.35)

Hello!

Could you share a larger image? I don’t know if I fail with the use of the forum but I can’t see it correctly…

Reading the error you share (in the thread title), I think it’s a validation failure, so I would check the text entered in the “content” field to see what is causing that error.