A widespread bug in the recent 375.86 GeForce driver release caused some Pascal cards to keep their VRAM clock at 810 MHz. Given that the nominal memory clocks for most Pascal cards to date range from 2 GHz to 2.5 GHz, that's a pretty serious bug. Owing to the seriousness of said bug, Nvidia now issued an hotfix driver version 375.95 to curtail the problem. The company says this beta driver addresses the VRAM clock issue on "certain factory-overclocked Pascal cards."
There's no word on the other known issues affecting recent GeForce drivers, though. Posters in the release thread for hotfix drivers are still complaining about a litany of issues, even though some of them don't appear to be Nvidia's fault, like flickering on SLI rigs in Battlefield 1 and Call of Duty: Infinite Warfare. A couple of forum posters are also complaining that the old high-refresh-rate power bug is back from the grave, too.
These drivers lack WHQL certification, so if you are on Windows 10 with the Anniversary Update and Secure Boot enabled, you'll have to wait for the next release. If you want to try your luck with 375.95, you can grab the new release here.