Thanks for your investigation and sharing. This is really useful. Indeed,
sudo mv /usr/lib/aarch64-linux-gnu/vlc/plugins/codec/libomxil_plugin.so /usr/lib/aarch64-linux-gnu/vlc/plugins/codec/libomxil_plugin.so.old
fixed it on my Xavier R32.4.2.
Best wishes to your wife with Nano ;-)