My company is migrating to SharePoint 2019 (on-premise) from SharePoint 2010. We migrated the content over, but when I click a link in the top navigation, some pages go to the classic view, while others are in a modern view. Also, when I click the main department page, it takes me to a "page not found" page, in classic view.
Is it possible to migrate the old site so that all pages are in the Modern view? I'm trying to avoid building all new pages in the modern site.