How to repair 2-manifold faces in Meshlab while preserving sharp features?

[mo1shang]

#"Repair non Manifold Edges" and "Repair non Manifold Vertices by splitting"
Windows, ML 202312.
I generated a triangular mesh using an open-source code, but the output mesh has inconsistent face normals.
Then, I tried to fix it using Meshlab's "Re-Orient all faces coherently", but it failed because the mesh model has 2-manifold faces.
I want to ask how to repair 2-manifold faces in Meshlab while preserving sharp features?
I tried using "Repair non Manifold Edges", but it resulted in the disappearance of sharp mesh corner points.
I also tried "Repair non Manifold Vertices by splitting", but it didn't work, and 2-manifold faces still exist.

[mo1shang]

fandisk.zip

[GiovanniSer]

Repair does not work. You can only select non manifold edges and delete these. It will delete all faces with the wrong normals, but also faces that unfortunately share their edges. But there's nothing else to do.
Just one try. Often faces with normal problems are duplicate faces looking from opposite sides. So you can try to remove the duplicate faces first.

[mo1shang]

Thank you for your reply, it was very helpful.