Open a new Draw document.
Choose a shape on the left, for example a rectangle.
Shape will get a blue background.
Have a look at the sidebar.
Properties will show Area → Fill → None
Bug appears on OpenSUSE 15.3 64bit rpm Linux with
Version: 18.104.22.168 / LibreOffice Community
Build ID: cf1691909b7b17c5e258d2635cae0072cf471be7
CPU threads: 6; OS: Linux 5.3; UI render: default; VCL: kf5 (cairo+xcb)
Locale: de-DE (de_DE.UTF-8); UI: en-US
Bug also appears with LO 22.214.171.124
Bug appears first here with LO 126.96.36.199, works well with LO 188.8.131.52.
Thanks Robert, already reported in bug 151188
*** This bug has been marked as a duplicate of bug 151188 ***