Contempo And The Missing Hamburger...
When Blogger rolled out new templates in 2017, the navigation scheme for the new templates was a bit different. Those of us who happened to have the screen width set below a given width, discovered that the sidebar menu was not visible on the home page unless you selected a "hamburger" icon on the top-left corner of the page. And, if you navigated to a post, the hamburger icon disappeared entirely, so, those of us with screen widths below a given width could not access the sidebar menu at all from post pages.