viz.plot_sensors() only partially honors axes parameter

[hoechenberger]

Describe the bug

I wanted to add sensor alignment plots via Raw.plot_sensors() to some subplots of a larger figure. While the sensors are getting plotted, I observe some very annoying side effects that imho qualify as bugs.

Steps to reproduce

import matplotlib.pyplot as plt
import mne
from mne.datasets import sample

data_path = sample.data_path()
fname = data_path + '/MEG/sample/sample_audvis_raw.fif'
raw = mne.io.read_raw_fif(fname)

fig, ax = plt.subplots(2, 2)

ax[0, 0].plot(range(10))
ax[0, 0].set_title('Title A')

ax[1, 0].plot(range(10))
ax[1, 0].set_title('Title B')

raw.plot_sensors(ch_type='mag', axes=ax[0, 1])
raw.plot_sensors(ch_type='grad', axes=ax[1, 1])

Expected results

All subplots should appear in their designated axes.

Actual results

• First sensor plot doesn't have a title
• Second sensor plot's title appears as suptitle while it should be an axes title
• The entire figure appears to be truncated at the top, left, and bottom

Additional information

The behavior reminds me somewhat of #7595, which has been fixed by @drammock in #7706.

I'm using Matplotlibs Qt backend on macOS.

[hoechenberger]

There also seems to be an issue with the "click on sensors" callback, which is linked across BOTH sensor subplots…

[agramfort]

I would qualify this as a bug

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