First important question, which LibreCAD version do you use?
It's not clear, but it seems, that for the referenced thread the solution was to upgrade to latest version.
The test file in the referenced thread works fine for me too, with the latest build, so can't reproduce it.
Have you downloaded the test file and checked if it shows the issue for you?
Can you append your DXF file or at least a reduced version which still has the issue?