Yes - this is all a combination of the packaging of Ubuntus LO version, the default packages being installed by Ubuntu and your desktop manager.
Kubuntu 18.04 Review
Kubuntu 18.04 Libreoffice 6 Interface Download
It might still be “hidden” as an experimental feature, but work on improving the LibreOffice ‘notebookbar’ continues apace.The Document Foundation say the Notebookbar is “significantly improved” in LibreOffice 6.1, with the tabbed version now considered ‘complete’ in the Writer application!The notebook bar remains a work in progress in other modules of the suite, but the aim is to eventually replicate a tabbed experience that is both as powerful and as simple as default toolbar-based GUI. Write Amazon’s next best-sellerA headline features of the LibreOffice 6.x series is the ability to export Writer documents to, the ubiquitous ebook format.LibreOffice 6.1 improves things further for all wannabe writers by including a greatly improved EPUB export filter:The dialog is better placed to handle link, tables, and images; supports font embedding and footnote support; and expands the range of metadata you can add/edit, e.g, ‘author’, ‘title’, ‘ISBN’.There’s also support for fixed layouts, the option to set a cover image, and, should you need it, the ability to use vertical writing! Little things that make life easierThere are also two somewhat minor features shipping in this release, but both will save you headache of menu surfing. Image: The Document FoundationA new option in header/footer menus lets you effortlessly insert page numbers in LibreOffice documents.And a new “cog” button in the “customize” dialog makes it much to customize, rearrange, rename, and reorder toolbars and top level menus to suit your tastes/needs/workflow.
You can download LibreOffice 6.1 for Windows, macOS and Linux from the official LibreOffice website.Ubuntu 18.10, due in October, will ship with LibreOffice 6.1 as part of the default install — but you don’t have to wait until then to get it!As well the official LibreOffice downloads available on the website (as above) you can also opt to or Snap versions.You will be able to upgrade to LibreOffice 6.1 on Ubuntu 16.04 LTS or later by adding to your software sources. At the time of writing 6.1 hasn’t been uploaded, but it should appear in the new week or two.Thanks TDF.