Can't overwrite blog page

Hi, i have a theme that let’s me change from classic view to masonry or grid. However i just can’t seem to add anything on to the blog page. It remains classic view. I can’t even add a banner above the page. Nothing works. I can make another page and it works fine there, but once i go to reading and set that page to blog, it reverts back to classic view. What would be the issue. thanks