QCAD Professional
Win installer 32bit
Version: 3.25.2.4 (3.25.2.4)
Internet: QCAD.org
Build Date: Nov 18 2020
Revision: 40f4475
Qt Version: 5.13.2
Architecture: i386
Compiler: Unknown

Most likely not related to the QCAD version, rather an old sore.

File included
Topic: https://qcad.org/rsforum/viewtopic.php?f=33&t=7889#p30803
Confirmed by 'cccplex' Linux 'Latest Ubuntu'

Polyline arcs with Width = 2R render as circle segments rather than circle sectors.
As Non-reversed arcs these don't explode.
As reversed arc these explode to a single arc rather than a circle sector contour.

There is also still the faulty rendering with Z not zero
FS#1923

Regards,
CVH