465.27
I had this problem and still have it with the new version.
However
I’ve read this
https://wiki.archlinux.org/index.php/NVIDIA/Troubleshooting#Overclocking_not_working_with_Unknown_Error
so I thought it might be a problem with gdm which starts Xorg rootless.
installed sddm and plasma to try both gnome and plasma on sddm. and it WORKED IN BOTH (fan,memory overclock,coreoverclock).
I don’t know why this problem appeared now I’ve always used gdm and it still works on older versions of the driver so maybe it’s a packaging trick that used to be done on arch downstream and now it doesn’t or a driver change that re-required root-Xorg.
I’ll post this here and on the arch downstream bug report.