@psantucc,
while the test package is being prepared, can you tell about the GPU model and drivers version?
It could also be useful to know about the GL/EGL version. To do that, you can run these commands in a terminal on the server:
glxinfo | grep "OpenGL version"
eglinfo | grep "EGL version"
Before that, you may need to install ‘mesa-utils’ package providing the glxinfo command.
Please also try to add this line into the /usr/NX/etc/node.cfg file on the server:
WaylandModes drm,egl,compositor
Then restart the NoMachine server. This will make an alternative capture method (“drm”) be used before the default one (“egl”). Does this workaround help?