Sidebars don’t appear where I’ve set them to be

I’m new to Bento, so I suspect I’m missing something, and it’s probably really simple.

The site should be set up with no sidebars on pages, but sidebars on the blog page and posts. I’ve got the customizer set up to use full width 1080, no sidebar. When I go to the main blog page and change that page to have sidebar on the right, nothing happens.

I did notice, also, that I only seem to have two spots to place widgets anyway — footer and header, so I’m not sure where I’d even begin to place the sidebar widgets.

The site is behind a wall right now, otherwise I could share the link. I can do screenshots, if needed. Thanks!