Plotting with 2D browser in a second process doesn't show the figure

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A bit of a niche use-case, but I am having trouble getting this to work: plot with the 2D browser backend in blocking mode in a child process.

For my use-case, I want to plot ICA sources; with something like that:

from pathlib import Path
import multiprocessing as mp

import mne

directory = Path(mne.datasets.sample.data_path())/'MEG'/'sample'
fname = directory/'sample_audvis_filt-0-40_raw.fif'
raw = mne.io.read_raw_fif(fname, preload=True)
raw.apply_proj()
raw.pick_types(eeg=True)

ica = mne.preprocessing.ICA(method='picard')
ica.fit(raw)


def plot(ica, raw):
    ica.plot_sources(raw, block=True, show=True)

if __name__ == '__main__':
    process = mp.Process(target=plot, args=(ica, raw))
    process.start()
    input('Press ENTER to kill process..')
    process.kill()

I do get in the IPython console:

Using matplotlib as 2D backend.
Figure(1679x995)

But no figure…
Same with a raw.plot():

from pathlib import Path
import multiprocessing as mp

import mne

# mne.viz.set_browser_backend('pyqtgraph')

directory = Path(mne.datasets.sample.data_path())/'MEG'/'sample'
fname = directory/'sample_audvis_filt-0-40_raw.fif'
raw = mne.io.read_raw_fif(fname, preload=True)
raw.apply_proj()
raw.pick_types(eeg=True)


def plot(raw):
    raw.plot(block=True, show=True)

if __name__ == '__main__':
    process = mp.Process(target=plot, args=(raw, ))
    process.start()
    input('Press ENTER to kill process..')
    process.kill()

Any idea what is making this difficult?