I have the same issue with a GTX 1080, running Hardware Configuration tool installs the Chaotic AUR version of the nVidia driver, but on reboot, the kernel does not boot.
Version 460 I believe was automatically chosen.
And on a related note, the ISO will not boot with a GTX 1080 if you use the Non-Free option, you have to use the Free Option to boot into the live environment.
I suspect it is something to do with the 5.10 kernel as installing that kernel on Kubuntu 20.10, my main installation it also prevents a boot.