On boot the plugin runs this command.
nvidia-smi --query-gpu=gpu_name,gpu_bus_id,gpu_uuid --format=csv,noheader | sed -e s/00000000://g | sed 's/\,\ /\n/g' > /tmp/nvidia
and outputs to a file /tmp/nvidia
When you go to the plugin page it reads the contents of that file to get the GPU info.
cat /tmp/nvidia
I can't tell you why your copy of that file is getting deleted, but that's what I would bet is causing it. Try running the above command and see what the output is, both from a fresh boot and after the problem occurs.
My guess is you have some cleanup script