Vertices are missing when trimesh.load(process=False)

[czpcf]

I loaded an obj file using trimesh.load, trying to keep original vertices and faces. However, some vertices are still missing with process=False.

Here is the obj:

o mesh
v 1 1 1
v 1 1 2
f 1 1 1

I loaded it with mesh = trimesh.load(path, process=False), and mesh.vertices equals TrackedArray([[1., 1., 1.]]), whose shape is not (2, 3).

How to load all vertices? Thank you in advance!