That is not using the Lambda Stack version. That is using the Ubuntu version. I would suggest switch to the Lambda stack.
LAMBDA_REPO=$(mktemp) &&
wget -O${LAMBDA_REPO} https://lambdalabs.com/static/misc/lambda-stack-repo.deb &&
sudo dpkg -i ${LAMBDA_REPO} && rm -f ${LAMBDA_REPO} &&
sudo apt-get update && sudo apt-get install -y lambda-stack-cuda
Then you would want to confirm, check for errors. And if all is alright, then reboot.
Also confirm you do not have the /etc/X11/xorg.conf
sudo mv /etc/X11/xorg.conf /etc/X11/xorg.conf.bad
mark