Hi,
Several months later, I am facing the same issue (empty visualizer, no errors etc.) with Geant4 version 11.2.1., installed on the last version of WSL2 (2.2.4.0).
I also found a post that has roughly the same problem here, but I did not found a solution for my problem there yet - I am already using the default Ubuntu terminal as said under dboccanf’s post.
When I do /vis/open TSG, the obtained viewer is already not completely clear but still does not show geometry.
I may try doing a reinstall leaving out the cmake prefix -DGEANT4_USE_OPENGL_X11, as stated in this post, but at this point I doubt it will solve my problem at all.
If I try and make an offscreen file as described in this post from another thread (empty viewer, Geant run on a VM), I get the same results as there.
Hope we can find a workaround.