Bug in sensors naming when using mne.viz.plot_topomap

Description of the problem

Hello,

I discovered a bug in the sensor name when using mne.viz.plot_topomap. The values on the topomap remain correct but not the names; which can lead to confusion if we want to draw conclusion based on quick visualisation of sensor names.

Steps to reproduce

import mne
import numpy as np 
# activate interactive plot if not already
# %matplotlib qt 

sample_data_folder = mne.datasets.sample.data_path()
sample_data_raw_file = (
    sample_data_folder / "MEG" / "sample" / "sample_audvis_filt-0-40_raw.fif"
)

# load the dataset
raw = mne.io.read_raw_fif(sample_data_raw_file)
raw.pick_types(meg='grad') # pick only gradiometers
raw.load_data()

# plot the sensors with their names using raw.plot_sensors
raw.plot_sensors(show_names=True)

# beta band
fmin = 13
fmax = 30
freqs_beta = {f'{fmin}-{fmax} Hz': (fmin, fmax)} # freq up to beta (13, 30) 

# compute psd and plot in beta band
raw_psd = raw.compute_psd(fmin=fmin, fmax=fmax)
raw_psd.plot_topomap(bands=freqs_beta, show_names=True)

# compute PSD and plot it
psds, freqs = mne.time_frequency.psd_array_welch(x=raw._data, sfreq=raw.info['sfreq'],
                                                 fmin=fmin, fmax=fmax, n_fft=2048, n_jobs=-1)

# just to check that the values are actually all the same 
assert np.all(raw_psd._data == psds), 'Raw PSD != psds'

# average the PSD over the frequency axis
psd_mean = np.mean(psds, axis=1)

# Plot the topomap of the Gradiometer power
mne.viz.plot_topomap(psd_mean, raw.info, show=True, res=300, sensors=True, names=raw.ch_names)

Link to data

No response

Expected results

raw.plot_sensors(show_names=True) should provide the following plot

raw_psd.plot_topomap(bands=freqs_beta, show_names=True)

So far this looks correct to me and I would expect mne.viz.plot_topomap to produce similar result as raw_psd.plot_topomap.

Actual results

But when doing mne.viz.plot_topomap(psd_mean, raw.info, show=True, res=300, sensors=True, names=raw.ch_names), I didn't expected to have this sensor names scheme. Unfortunately there is no colorbar option using mne.viz.topomap to my knowledge so the color-scheme is slightly different but I checked that the values where the same earlier)

Additional information

Let me know if there is something that I am missing here. Thanks for your support.

mne-tools / mne-python