Can't change container size for single posts

I have my homepage layout as sidebar/content - I have increased the size of my homepage container to where I want it.

I did have my single post displaying with no sidebar. I now want to have the same layout as my homepage, Sidebar/content.

I did make that change but the single post container is not the same size as my homepage, it’s smaller. I would like it to be the same size.

I have been in the customizer and went to a post and increased the size of the container and it shows the post container larger. I publish, but when I go to my site and go to a post the container size has not increased in size as I did when in the customizer. I have cleared cache, but no change.

The homepage container is the size I want but I can’t get the single post container to match the homepage container size. How can I do this?

Any help would be appreciated
Leo