Lattice rotation deformation problem

Hello. I’ve noticed that when rotating a lattice in edit mode, with a mesh object being modified by it, the mesh gets ‘flattened’ or squished into a square shape, even if the lattice proportions stay the same. The problem nearly goes away when the lattice is sliced 13 time or so in each direction, but it’s really bothering me. Is this a bug? How can I fix this?