Due to the structure of the page, you cannot use full-width or wide-width layout in the new WordPress editor if you are also using two-column layout in Graphene. Doing this will result in the block element to go behind the sidebar, as you have discovered.
If you’d like to use full-width or wide-width layout, you’ll need to set the page to use the Single Column template. This will remove the sidebar and you’ll have the full width of the page for content.