Update : I used the boost mode of my CPU (i5 6500) and tadaaa : Connected ! It might be somthing else, I don't know actually. But if it can help someone else...
Suprisingly, even with my "small" hardware (1060 6Gb, ssd, 16Go 2133Mhz RAM), I'm having a pretty decent game sessions. Even in the district market, the framerate is not that low.
Some fps drop and random crash time to time (like once in 2 hours) but I'm really enjoying this !