Nsight Compute metrics value confused

Hi, I am testing MPS on Quadro RTX 6000. Whether MPS is enable or not, I start two processes, they all launch kernel on GPU(first process configuration:vector_add<<<1,1>>>, second process configuration:vector_add<<<1,32>>>). And I profile the second process using nsight compute command line(using ncu to start the second process with --metrics option). But what i am confused is that the two ncu reports data(enable MPS case ncu report and disable MPS case report) show that sm__warps_launched.avg, sm__warps_launched.max, sm__warps_launched.sum and other metric values are different, but sm__warps_active.avg.pct_of_peak_sustained_active(achieved occupancy) is same, i think that after enabling MPS the achieved occupancy value should be double. The below show the ncu report data.

MPS is disable:
vector_add(float *, float *, float *, int), 2021-Dec-03 18:36:32, Context 1, Stream 7
Section: Command line profiler metrics
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sm__warps_launched.avg warp 0.01
sm__warps_launched.max warp 1
sm__warps_launched.min warp 0
sm__warps_launched.sum warp 1
smsp__warps_launched.avg warp 0.00
smsp__warps_launched.max warp 1
smsp__warps_launched.min warp 0
smsp__warps_launched.sum warp 1
smsp__warps_launched_total.avg warp 0.00
smsp__warps_launched_total.max warp 1
smsp__warps_launched_total.min warp 0
smsp__warps_launched_total.sum warp 1
sm__warps_active.avg.pct_of_peak_sustained_active % 3.12
---------------------------------------------------------------------- --------------- ------------------------------

MPS is enable:
vector_add(float *, float *, float *, int), 2021-Dec-03 18:10:45, Context 1, Stream 7
Section: Command line profiler metrics
---------------------------------------------------------------------- --------------- ------------------------------
sm__warps_launched.avg warp 0.03
sm__warps_launched.max warp 2
sm__warps_launched.min warp 0
sm__warps_launched.sum warp 2
smsp__warps_launched.avg warp 0.01
smsp__warps_launched.max warp 1
smsp__warps_launched.min warp 0
smsp__warps_launched.sum warp 2
smsp__warps_launched_total.avg warp 0.01
smsp__warps_launched_total.max warp 1
smsp__warps_launched_total.min warp 0
smsp__warps_launched_total.sum warp 2
sm__warps_active.avg.pct_of_peak_sustained_active % 3.12
---------------------------------------------------------------------- --------------- ------------------------------

Nsight Compute does not support profiling with MPS enabled, see Release Notes :: Nsight Compute Documentation

Profiling with enabled multi-process service (MPS) can result in undefined behavior.