I had the same issue. I was using the latest fast ring at the time. .81 was fine, .91 would give the ~11% Nvidia Container LS CPU usage. I finally gave up trying to resolve it and did a clean install of 1809. I'm currently running .91 which was clean installed using the Nvidia installer, no stripping out the driver or other tricks and no GeFarce. Just driver, sound,and PhysX. I uncheck the 3D components as I don't use them. No issues at all with CPU usage. Going to stay on RTM for awhile.