I discovered an optimisation bug.
CPU: AMD Ryzen 3 2200G
GPU: GTX 1060 3GB
OS: Windows 10
Drivers up to date
If I launch the game and load a savegame normally, my framerate if very bad. I've between 10-25FPS
I've seen comments on YouTube that gave a technique to fix this framerate bug, so here is what to do :
When launching the game, launch the benchmark 2 times:
The first time, 25FPS
The second time, 45FPS
And then, when I load my savegame, I've 50FPS
I hope it'll be fixed in the next update.