When in Libreoffice programs e.g. Writer, the Windows 10 Taskbar will not autohide. (It does in the Desktop, etc.) Neither can I drag it down out of the way in Libreoffice.
I cannot confirm that because it works for me.
With me Windows 10 Home; Version 1909; 64-Bit | LibreOffice, Version: 6.4.0.3 (x64).