Bad geometry after cut operation on simple model

[eparadis]

Description of the bug

I loaded a 3MF file produced by OpenSCAD and did a cut operation in PrusaSlicer. ~One~ Both of the resulting two halves has bad geometry that PrusaSlicer detects and will then not slice correctly. 

Project file & How to reproduce

1. Open the project file from before the cut operation
2. Select the object
3. Click the Cut tool icon
4. (it defaults to mid-model, which is the correct location)
5. Add connectors around the perimeter as shown
6. Select "flip upside down" for Object A
7. Click "Perform cut"
   • Expected: the object is split in half with correct geometry and can be sliced and printed
   • Actual: the object appears cut correctly in 3D Editor view, but the object list shows errors, and slicing view shows open edges.

Notes:

• even with no connectors, the model geometry problems will occur
• sometimes the cut operation results in 18 open edges and sometimes only 3. I don't know why.

before the cut operation: manifold_2x1_25hex - before cut operation.3mf.zip

after the cut operation: manifold_2x1_25hex - bad cut.3mf.zip

Checklist of files included above

• [X] Project file
• [X] Screenshot

Version of PrusaSlicer

2.7.2+MacOS-arm64

Operating system

MacOS Sonoma 14.3.1

Printer model

Prusa MINI+

edit: I realized that both of the halves contain bad geometry, as shown in the screenshots.

[u89djt]

Windows user having a go: both files work without (additional) errors or missing solids for me in 2.7.2 under windows 10. I didn't have the mini profile as part of my standard settings so it was temporarily installed by the slicer for each of these files. Here's a project file of the uncut object imported into the slicer, then cut and connectors added, and the result saved. u89djtcutofmanifold_2x1_25hex - before cut operation.zip

[eparadis]

I closed PrusaSlicer and opened the "before cut operation" version and repeated my steps because I wanted to capture a screenshot of the case when it only has 3 open edge errors. But... it magically fixed itself? Here is the project at that point: manifold_2x1_25hex - after cut operation - magically fixed.3mf.zip

Hopefully someone can look at the various versions included and determine what sort of subtle situation is happening here.