Hi @Stysch
It looks like half your cells are inverted (and most of them are declared as hexahedron but should be tetrahedron anyway).
It looks like ParaView nows try to “respect” inverted hexadron so they show up like this.
But you actually can fix your mesh in ParaView!
Add a Tetrahedralize and a CleanCellsToGrid filter to get your correct data (as tetrahedron):
