PartDesign: Rendering bug with polar array (not OCC related)

Problem description

I used the polar array/pattern to step and repeat a clip feature and found a strange bug.

The clip feature is created from a number of other features as a group.

See attached file FreeCAD and .3mf files (.gz as GH does not like .FCStd/.3mf files)

The design features a rotated pattern of three 'bayonet style' clips.

Of the clips, after the pattern is applied, the copy that is also the original shows both the state prior to the chamfer and the state after. The removed material is not removed. But it seems somehow separate though not in a new body. Before the polar array feature is added the original renders correctly. On the two copies this is not the case. They render correctly. If you export the model the exported .3mf renders correctly indicating a rendering issue, not a modelling issue.

Original files, images and generated output attached.

Version: OS: KDE Flatpak runtime (X-Cinnamon/lightdm-xsession/xcb) Architecture: x86_64 Version: 1.1.1.44874 (Git) Build date: 2026/04/14 22:09:59 Build type: Release Hash: 0108fd4b4850cc46e625b60e53cea7a7bbe69f8d Python 3.13.13, Qt 6.10.3, Coin 4.0.8, Vtk 9.4.2, boost 1_86, Eigen3 3.4.1, PySide 6.10.3 shiboken 6.10.3, SMESH 7.7.1.0, xerces-c 3.3.0, IfcOpenShell 0.0.0, OCC 7.8.1 Locale: English/United States (en_US) Navigation Style/Orbit Style/Rotation Mode: Revit/Rounded Arcball/Window center Stylesheet/Theme/QtStyle: FreeCAD.qss/FreeCAD Dark/ Logical DPI/Physical DPI/Pixel Ratio: 96/30.48/1

Workbench affected?

None

Steps to reproduce

Design file (containing rendering issue) side-adapter1+rendering-bug.FCStd.gz

Output file (not containing artefacts of the issue) side-adapter1-Body +no-rendering-bug.3mf.gz

Expected behavior

The original copy of the rotationally copied group of features should render as it's siblings. All three copies should look like this.

This is the same model as in the "actual behaviour" just rotated to make this artefact visible. There is no orientation that can show both good a bad clips at the same time.

Actual behavior

The original copy of the rotated pattern has both the correct and incorrect rendering superimposed, see 'squared off' clip in the image

This is the same model as in the "expected behaviour" just rotated to make this artefact visible. There is no orientation that can show both good a bad clips at the same time.

Development version About Info (in Safe Mode)

I will do this if this issue can't be re-created. I can only run the flatpak and in the middle of other work. I don't want to break that environment for a trivial issue that is not materially effecting my output and can easily be validated by simply opening the attached files.

Last known good version (optional)