qtdragon crash during 3d viewer translation (QTvcp ERROR! Message # 1)

I effectively use an NVIDIA 1070 GPU (overkill, but that's what I have and there is no onboard GPU).

GL_RENDERER = NV134
GL_VERSION = 4.3 (Compatibility Profile) Mesa 22.3.6
GL_VENDOR = nouveau
GL_EXTENSIONS = (There is a huge quantity of things, do you really want to see them?

I have 2 PCIe AMD GPUs that I have no use for (too old for 3D stuff becaue AMD only provides support for like 3 years, plus I don't use PCs).

I wish we could trade GPUs.

AMD/ATI stuff works well on Linux because the drivers are in the kernel, though OpenCL is patchy.

NVIDIA GPUs work great on Linux for headless compute, but not always for rendering stuff.

Software is fine, but is seems like such a shame to use software rendering when you have a good GPU.

Are the proprietary NVIDIA drivers an option?

Please post output of glxgears -info.

glxgears -info usually prints out the actual name of your GPU, not just "NV134"; weird.
Though though the fact that glxgears works perfectly whilst QTvcp crashes is even weirder.

Did you eventually manage to get the NVIDIA rendering to work?

Ubuntu and GhostBSD (and probably others as well) install the proprietary NVIDIA driver (not the latest version, generally 535, or 470 if the GPU does not support driver version 535) for supported NVIDIA GPUs by default when you install the OS, which should really be the case for all Linux distros.

Windows also installs the proprietary NVIDIA driver automatically, if your GPU is at all supported. However, it installs a really old version (450, I think), even if your GPU supports the latest driver, which is stupid.

You could try running:
sudo apt update
sudo apt install nvidia-driver-full
sudo reboot

WARNING: THIS MAY BREAK YOUR SYSTEM
Consider making a backup of your system first, or asking for advice regarding the nvidia-driver package and the preempt_rt kernel and just Debian in general.
If you have an unused HDD or SSD, consider taking out your working setup's drive and putting in the empty one, then installing the LinuxCNC 2.9.4 ISO to that, and then trying out those commands to install the "real" NVIDIA drivers, so you won't risk breaking your working install and setup.