Can′t apply right and left margin to the text in the blog

Hi,

I have a problem, when I create a new post, I can′t apply right and left margin. I change the container values in the customizaer but it remains the same. You can see the post:
https://incluya.art/2024/04/22/documental-accesible-donde-acaba-la-memoria/

Can you please help me? The other pages are within block containers, in this case I don ′t have any problem.

Thanks and regards,
Ana

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