Inspecting your mesh, i see that there are more points in your mesh than those that are part of the cells:
(Pdb++) triangle_mesh.points.shape
(64010, 2)
(Pdb++) len(np.unique(triangle_mesh.cells_dict["quad"].reshape(-1)))
63593
which is problematic.
This is probably due to the definition of Transfinite surfaces after making Physical Surface and Physical Curve.