NVIDIA-SMI 450.57 Driver Version: 450.57 CUDA Version: 11.0
No idea if it fixes the P-States in Plex - but thats the version currently in 6.9 beta24
Edit:
It does work for some AI stuff I am playing with though -->
Every 1.0s: nvidia-smi gputest: Sat Jul 11 23:50:18 2020
Sat Jul 11 23:50:18 2020
+-----------------------------------------------------------------------------+
| NVIDIA-SMI 450.57 Driver Version: 450.57 CUDA Version: 11.0 |
|-------------------------------+----------------------+----------------------+
| GPU Name Persistence-M| Bus-Id Disp.A | Volatile Uncorr. ECC |
| Fan Temp Perf Pwr:Usage/Cap| Memory-Usage | GPU-Util Compute M. |
| | | MIG M. |
|===============================+======================+======================|
| 0 Quadro P400 Off | 00000000:0B:00.0 Off | N/A |
| 34% 32C P8 N/A / N/A | 771MiB / 2000MiB | 0% Default |
| | | N/A |
+-------------------------------+----------------------+----------------------+
+-----------------------------------------------------------------------------+
| Processes: |
| GPU GI CI PID Type Process name GPU Memory |
| ID ID Usage |
|=============================================================================|
| 0 N/A N/A 7163 C python3 769MiB |
+-----------------------------------------------------------------------------+