Poor graphical performaces in DirectX 11 only

I get very poor performance when DirectX 11 is enabled.

My config is:
AMD Ryzen 5 3600
16 Go DDR4
NVIDIA GeForce RTX 3060

Note I have no problem with other games

With DirectX 9 selected, 1080p full quality I reach ~130 FPS ingame

But when DirectX 11 is selected, when choosing character am at around 4 FPS.
Even with lowest quality and full performance I have max 20 FPS ingame.
It is not really about FPS drop as I saw in other topics. The FPS is always low.

I tried a lot of things: re-installing on SSD instead of HDD, re-install Steam, switch off Gsync, vertical sync, switch fullscreen/bordeless, update, re-install and reset NVIDIA drivers

My best guess is it should be about the GPU as I can see in Afterburner that the core clock stays at low frequency.

Any solution very welcome :slight_smile: