PyVista not working: black screen but no error message?

Hello everyone,
I’m quite new to Fenics so I excuse myself if mine is a silly problem.

I’m a Windows user so I installed fenicsx on WSL2 (Ubuntu) through anaconda and everything seemed to be ok.
However, I have a problem with PyVista: when it opens up it’s always black and nothing can be seen, but no error message is produced.

I’ve tried with the poisson demo and PyVista has the strange behaviour above, but also with a simpler code like:

import pyvista as pv
from pyvista import examples
vol = examples.download_knee_full()
pl = pv.Plotter(off_screen = True)
pl.add_volume(vol, cmap="bone", opacity="sigmoid", show_scalar_bar=False)
pl.enable_depth_peeling()

figure = pl.screenshot("initial1.png")

The screenshot produced is all black, as you can see here:

I don’t know if there was a problem with the installation or something else, does someone know how can I fix this?

Sorry, that’s a question solely on pyvista, and must be asked at pyvista support at pyvista/pyvista · Discussions · GitHub