View not showing trajectory with Vasp calculator

According to docs a trajectory can be viewed. But using view trajectory (prop_opt.trajectory,) returns without doing anything: no error message neither picture is shown. The property looks like this

prop_opt = Property energy, forces, trajectory ((calculator: calc_opt), (structure: Pd112_6H2O), (constraints: (constr_fix_2_bottom,)))

where calc_opt is a vasp calculator with ibrion: 2.

But the trajectory is correctly produced and stored because it still can be viewed using this workaround:

view structure (prop_opt.trajectory[0].structure,)

MWE: Add a model using the script trajectory_vasp.vm in the examples folder and then add:

view trajectory (prop.trajectory)