"Failed to initialize NVML: Driver/library version mismatch" - is Ubuntu server auto-updating?

I just received this message on my Ubuntu server:

Failed to initialize NVML: Driver/library version mismatch

when typing

watch nvidia-smi

I am running ubuntu server (Ubuntu 18.04.5 LTS), and everything was working correctly yesterday.

So the question is, did ubuntu server automatically update the Nvidia driver without asking me for permission? How would I confirm this? I don't want automatic updates!

I realize that a reboot will fix this, but this is server doing lots of other stuff, so rebooting in the middle of the week is not allowed :)

thanks!