Hello,
Little update, i removed nvidia-dkms, install nvidia-hook then nvidia, but nothing change, every single game I tested crashed.
So i’m back at the begining. Maybe the next update of those 3 package will solve my problem.
And envycontrol is really much like optimus-manager, so that’s cool. I’m using it right now in hybrid mode and it works great. Thanks for advising me to use it.
Once again, thanks everyone for your help 
This was also my “snooze solution” until now, but I kinda need to clear it…
I have uninstalled optimus-manager and now looking for solutions…
Hello,
So far, nothing work great.
The latest lib32-nvidia-utils, nvidia-dkms and nvidia-utils package changed nothing.
Envycontrol, changed nothing. If i use the hybrid mode, game freeze.
So for now, i am back on optimus-manager-git, and use the nvidia mode (not the hybrid).
i have installed envycontrol and switched manually to nvidia and tried Red Dead Redemption 2. It seems to work. I will install now the envy control to see if it will also work…
coming back with report: nvidia mode seems to work, hybrid mode seems not to work.
I also suspect that this was what was broken with optimus-prime: it seems the “handover” to the dedicated gpu is not working…