Hello @BB_One:
Demo content won’t work because it’s static. Instead, use page content and manually translate the grid content into the language you want. Then switch the language using the language switcher in both the editor and the frontend.
If you create a page for another language, you must switch to that language to view that page.
When you change the language, you also need to select the correct page in the customizer. The page does not change automatically when you switch languages.
To disable translation, simply don’t translate the content into other languages.
Sincerely,
Minal