NVIDIA Optimus, GPU not going into low power state

I am using a Lenovo P1 Gen 2 with an Intel i9-9880H, Quadro T2000, NVIDIA 510.47.03, linux kernel 5.15.26_1, CUDA 11.6. For the life of me, I cannot get the GPU to go into a power state lower than P8, even when nothing is running on the GPU and have no external monitors attached.

nvidia-smi shows no running processes.

Adding the pm rules and nvidia dynamic power management here causes the driver to crash, and it loads nouveau:

I cannot get power consumption below ~15W. When I use bbswitch and turn the GPU off, power consumption immediately drops to 5-7W. So, when I run with the GPU on, I’m doubling my power consumption for nothing. How can I get the dGPU to go into a low power mode?