LrC Performance Tab vs Nvidia App Optimization

Lightroom 15.4.1 on Windows.

As GPU I have an NVIDIA 4070 with 12GB of VRAM, latest studio driver  6.10.62.

In the Graphic tab of the NVIDIA App I can choose to "Optimize" LrC, but if I do then in LrC settings under Performance tab it sets automatically CUSTOM under "Use GPU", option "GPU for export" is disabled and greyed out and it says I have only "Partial graphic acceleration".

If I manually force AUTO under "Use GPU" than when i go back to NVIDIA App it says LrC is not optimized, and if I select OPTMIZE again than under LrC Performance it goes back to partial accelleration.

Any idea?