Error Fetching Keys from Repo - Ubuntu 1804 CUDA Driver installation

Hello! I have been using a script which installs Cuda drivers on clusters in Azure. Today however, the script suddenly failed. Installed a test machine and ran the script, found out the culprit being this line:

sudo apt-key adv --fetch-keys

Machine isn’t fetching the key, with the following error popping up:

Executing: /tmp/tmp.fFa624xbp6/ --fetch-keys
gpgkeys: no key data found for
gpg: no valid OpenPGP data found.
gpg: Total number processed: 0
gpg: keyserver communications error: key not found
gpg: keyserver communications error: bad public key
gpg: WARNING: unable to fetch URI bad public key

Again, this has never happened before in the 6 or so months i have been using the setup. I tested machines across three different regions, getting the same error. Also tested on 16 and 20 versions. I do not think the issue is at my end, and that there’s something wrong with the key itself or Nvidia server side.

Any help with this or any ideas how to go about installing drivers? Needs to be scriptable because installing across 100s of nodes manually isn’t feasible.

Thanks for any information on this.