QCAD Version: 3.32.9
Downloaded package (file name): qcadcam-3.32.9-pro-linux-qt5.14-x86_64
Operating System: Linux Mint 22.3 x86_64 / DE: Cinnamon 6.6.7
I have attached my drawing file (DXF/DWG)
D2 / Break Out Segment “Trim” / Unexpected Additional Entities
See Attached dxf and gif below.
D2-Trim-Error.dxf (153.5 KB)
This should be fixed for an upcoming release.
Splitting an arc as full circle at two given split-points may result in an unexpected shape, even in a more than fully circular arc.
bambuko’s reported issue with HS is related to that.
Limiting an indicated arc to a connected segment for a boundary contour.
The flaw also affects Modify .. BreakOut and a new test case is added (hits 1& 2 in that commit)
But it may even that you stumbled on an exception that is not addressed by this fix.
A patch to a former patch (Apr 22 2026).
Sometimes an update is not for the best. 
Regards,
CVH
@John_Hyslop Thanks, this has already been fixed for the next release.