mne.viz.plot_alignment - sensors not displayed

While plotting MEG sensors with

fig = mne.viz.plot_alignment(raw.info, trans=trans, subject=subject, subjects_dir=subjects_dir,
                              surfaces=['head-dense', 'white'], meg=True,  show_axes=True, coord_frame="meg", src=src, dig=False)


mne.viz.set_3d_view(fig, azimuth=0, elevation=0, distance=1.5, focalpoint=(0., 0., 0.))

I got helmet surface but not locations of sensors. I did not get any error. Is this a visualization problem?

All the best,
Tomasz