You previously said it was the main blog page and that there is a block error, but when I view that page I cannot see any errors and the page is not defined as the main blog page.
Sorry, I do not understand what the issue is?
The “Boletines Semanales” section on your homepage is the theme’s “Recent Posts” section. This cannot be changed to show posts from different categories.
To do this you should use the CoBlocks posts block in the page content of the page. This is the main content area of the page when you edit it in the page editor, not the “Recent Posts” section of the customizer.